MAF On a 95 vortec

Question:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is used. When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to read barometric pressure (engine not running; manifold pressure = barometric pressure). Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), but that was changed to the ‘measure BARO while starting’ system.

– Hide quoted text — Show quoted text -> There is a baro sensor in some autos called the MAP sensor. This one mounted > on the > throttle body and senses the atmospheric pressure. It measures the pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a > dealer says > he changes a MAP or a MAF which look like the same sensor. > The MAP is actually there mainly to measure the intake manifold vacuum, > not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > > The dealer may have been talking about the intake air temp sensor in the > air > > intake. > > The MAP is the manifold absolute pressure measurement in the throttle > body > > that measures atmospheric pressure to adjust for altitude/barometric > > pressures. > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > > Less oxygen in > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > one-half atmosphere, or only half the air at sealevel. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > > which > > > >would be in the intake tract, they said "No, we just replace them", > at > > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is > it > > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Just going from the service manual description of the sensor. The mass air flow is affected by the altitude. The higher the altitude, the less air.

– Hide quoted text — Show quoted text -> The ‘barometric pressure sensor’ is in reality the MAP sensor, when one is > used. > When the key is turned from ‘off’ to ’start’, it passes thru ‘run’.  In the > brief time that it is in the ‘run’ position, the ECM uses the MAP sensor to > read barometric pressure (engine not running; manifold pressure = barometric > pressure). > Some early ECM vehicles, had both (79-80-81 3.8 Buick-engined GM vehicles), > but that was changed to the ‘measure BARO while starting’ system. > There is a baro sensor in some autos called the MAP sensor. This one > mounted > on the > throttle body and senses the atmospheric pressure. It measures the > pressure > and amount of air entering the engine. This sounds like a MAF and a MAP in > one sensor. > Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if > a > dealer says > he changes a MAP or a MAF which look like the same sensor. > > The MAP is actually there mainly to measure the intake manifold vacuum, > not > > the outside pressure. I believe that often the outside air pressure is > > measured at startup and at WOT using the MAP sensor. You’re thinking of > a > > BARO sensor, I think, usually there is no separate sensor for that. > > — > > Robert Hancock      Saskatoon, SK, Canada > > Home Page: http://members.home.net/hancockr > > > The dealer may have been talking about the intake air temp sensor in > the > > air > > > intake. > > > The MAP is the manifold absolute pressure measurement in the throttle > body > > > that measures atmospheric pressure to adjust for altitude/barometric > > > pressures. > > > Driving at sealevel vs 5000 feet makes a difference in the air/fuel > mix. > > > Less oxygen in > > > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in > about > > > one-half atmosphere, or only half the air at sealevel. > > > > if you have a MAP sensor, you don’t have a MAF > > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the > MAF, > > > which > > > > >would be in the intake tract, they said "No, we just replace them", > at > > > $105 > > > > >each.  I don’t even think there is an intake air temp. sensor on > this > > > motor, I > > > > >think the computer uses the water temp. to determine cold or hot > > starting > > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > > > sensor I’m > > > > >thinking of as the "air intake sensor", so it could be either. > > > > >> I think you meen the air intake temp sensor just above the egr is > it > > > ??? > > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the > intake > > > tube, > > > > >> right > > > > >> > before the snorkle.  MAP is right behid the snorkle mounted > between > > > > >> "bumps" on > > > > >> > the plenum. > > > > >> > > No it is not like th 94 – and i think you are looking at the > map > > > sensor > > > > >> and > > > > >> > > i am not sure if it does the MAF job too > > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > > "black > > > > >> spider" > > > > >> > > > on top?", it’s in the flexible plastic part of the intake > tube, > > > right > > > > >> by > > > > >> > > > the snorkle on the upper plenum. > > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Book just says it’s the intake air sensor, no "mass" or "temperature" in there. Auto parts stores don’t carry them, not the 2 big ones around me anyway.  I specifically asked the dealer for the "Mass Airflow Sensor", he gave me a price.  Makes me believe there is one. – Hide quoted text — Show quoted text – > Might try going to an auto parts store and check with the parts man or find > a service manual. Then if the dealer is blowing smoke you can show him in > the book and have > him compare that with what he claims he knows. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ??? > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The MAP is actually there mainly to measure the intake manifold vacuum, not the outside pressure. I believe that often the outside air pressure is measured at startup and at WOT using the MAP sensor. You’re thinking of a BARO sensor, I think, usually there is no separate sensor for that. — Robert Hancock      Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr

– Hide quoted text — Show quoted text -> The dealer may have been talking about the intake air temp sensor in the air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > >would be in the intake tract, they said "No, we just replace them", at > $105 > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it > ???

– Hide quoted text — Show quoted text -> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > >> and > >> > > i am not sure if it does the MAF job too > >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

There is a baro sensor in some autos called the MAP sensor. This one mounted on the throttle body and senses the atmospheric pressure. It measures the pressure and amount of air entering the engine. This sounds like a MAF and a MAP in one sensor. Ref: Haynes 1998 Cavalier and Pontiac Sunfire. I can see the confusion if a dealer says he changes a MAP or a MAF which look like the same sensor.

– Hide quoted text — Show quoted text -> The MAP is actually there mainly to measure the intake manifold vacuum, not > the outside pressure. I believe that often the outside air pressure is > measured at startup and at WOT using the MAP sensor. You’re thinking of a > BARO sensor, I think, usually there is no separate sensor for that. > — > Robert Hancock      Saskatoon, SK, Canada > Home Page: http://members.home.net/hancockr > The dealer may have been talking about the intake air temp sensor in the > air > intake. > The MAP is the manifold absolute pressure measurement in the throttle body > that measures atmospheric pressure to adjust for altitude/barometric > pressures. > Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. > Less oxygen in > higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about > one-half atmosphere, or only half the air at sealevel. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

No electrical connection on the airbox.  Maybe it is, but why would the parts department give me a price on a non-existant part? – Hide quoted text — Show quoted text – > Intake air temperature sensor? > Most times they’re on the filter box, tho. > Then what’s the little sensor sticking up right before the throttle body > in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > wasn’t replacing the part if it might have been the problem. > > if you have a MAP sensor, you don’t have a MAF > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > >think the computer uses the water temp. to determine cold or hot > starting > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > >thinking of as the "air intake sensor", so it could be either. > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > >> right > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > >> "bumps" on > > >> > the plenum. > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > >> and > > >> > > i am not sure if it does the MAF job too > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > >> spider" > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > >> by > > >> > > > the snorkle on the upper plenum. > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

The dealer may have been talking about the intake air temp sensor in the air intake. The MAP is the manifold absolute pressure measurement in the throttle body that measures atmospheric pressure to adjust for altitude/barometric pressures. Driving at sealevel vs 5000 feet makes a difference in the air/fuel mix. Less oxygen in higher altitudes. Even higher altitudes, ie, Pike’s Peak results in about one-half atmosphere, or only half the air at sealevel.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Might try going to an auto parts store and check with the parts man or find a service manual. Then if the dealer is blowing smoke you can show him in the book and have him compare that with what he claims he knows.

– Hide quoted text — Show quoted text -> if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text ->> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

Then what’s the little sensor sticking up right before the throttle body in the intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I do have a MAP sensor, I said that earlier in this post), but it’s $105!.  I didn’t ask him where this sensor is, since I was pretty sure I knew, and was positive I wasn’t replacing the part if it might have been the problem. – Hide quoted text — Show quoted text – > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. >> I think you meen the air intake temp sensor just above the egr is it ??? >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, >> right >> > before the snorkle.  MAP is right behid the snorkle mounted between >> "bumps" on >> > the plenum. >> > > No it is not like th 94 – and i think you are looking at the map sensor >> and >> > > i am not sure if it does the MAF job too >> > > > Yes.  If it’s the same design as the 94 (does it have the "black >> spider" >> > > > on top?", it’s in the flexible plastic part of the intake tube, right >> by >> > > > the snorkle on the upper plenum. >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) >> > > > > Has a mass air flow sensor and where it is ????

Response:

No idea about why, but I’m going on my experiences with late 80’s early 90’s FWD cars….LeSabres, Bonnevile’s, etc. Sorry not to be of more help. – Hide quoted text — Show quoted text – > No electrical connection on the airbox.  Maybe it is, but why would the parts > department give me a price on a non-existant part? > Intake air temperature sensor? > Most times they’re on the filter box, tho. > > Then what’s the little sensor sticking up right before the throttle body > in the > > intake tube?  I do have a MAP sensor, but this little sensor is bugging me > now as > > to what it is.  This is on the first gen. Vortec, the one with the "Black > Spider" > > upper plenum.  I also went to a dealer and asked what a MAF sensor for a > 94 S-15 > > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price > (yes, I > > do have a MAP sensor, I said that earlier in this post), but it’s $105!. > I didn’t > > ask him where this sensor is, since I was pretty sure I knew, and was > positive I > > wasn’t replacing the part if it might have been the problem. > > > if you have a MAP sensor, you don’t have a MAF > > > if you use an airflow sensor, manifold air pressure dont’ mean jack. > > > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, > which > > > >would be in the intake tract, they said "No, we just replace them", at > $105 > > > >each.  I don’t even think there is an intake air temp. sensor on this > motor, I > > > >think the computer uses the water temp. to determine cold or hot > starting > > > >situation.  I could be wrong, the Hayne’s manual just refers to the > sensor I’m > > > >thinking of as the "air intake sensor", so it could be either. > > > >> I think you meen the air intake temp sensor just above the egr is it > ??? > > > >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake > tube, > > > >> right > > > >> > before the snorkle.  MAP is right behid the snorkle mounted between > > > >> "bumps" on > > > >> > the plenum. > > > >> > > No it is not like th 94 – and i think you are looking at the map > sensor > > > >> and > > > >> > > i am not sure if it does the MAF job too > > > >> > > > Yes.  If it’s the same design as the 94 (does it have the > "black > > > >> spider" > > > >> > > > on top?", it’s in the flexible plastic part of the intake tube, > right > > > >> by > > > >> > > > the snorkle on the upper plenum. > > > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > >> > > > > Has a mass air flow sensor and where it is ????

Response:

Intake air temperature sensor? Most times they’re on the filter box, tho. – Hide quoted text — Show quoted text – > Then what’s the little sensor sticking up right before the throttle body in the > intake tube?  I do have a MAP sensor, but this little sensor is bugging me now as > to what it is.  This is on the first gen. Vortec, the one with the "Black Spider" > upper plenum.  I also went to a dealer and asked what a MAF sensor for a 94 S-15 > Jimmy with the 4.3L "W" engine would cost.  Guess what, he gave me a price (yes, I > do have a MAP sensor, I said that earlier in this post), but it’s $105!. I didn’t > ask him where this sensor is, since I was pretty sure I knew, and was positive I > wasn’t replacing the part if it might have been the problem. > if you have a MAP sensor, you don’t have a MAF > if you use an airflow sensor, manifold air pressure dont’ mean jack. > >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which > >would be in the intake tract, they said "No, we just replace them", at $105 > >each.  I don’t even think there is an intake air temp. sensor on this motor, I > >think the computer uses the water temp. to determine cold or hot starting > >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m > >thinking of as the "air intake sensor", so it could be either. > >> I think you meen the air intake temp sensor just above the egr is it ???

> >> > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > >> right > >> > before the snorkle.  MAP is right behid the snorkle mounted between > >> "bumps" on > >> > the plenum. > >> > > No it is not like th 94 – and i think you are looking at the map sensor > >> and > >> > > i am not sure if it does the MAF job too

– Hide quoted text — Show quoted text -> >> > > > Yes.  If it’s the same design as the 94 (does it have the "black > >> spider" > >> > > > on top?", it’s in the flexible plastic part of the intake tube, right > >> by > >> > > > the snorkle on the upper plenum. > >> > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > >> > > > > Has a mass air flow sensor and where it is ????

Response:

if you have a MAP sensor, you don’t have a MAF   if you use an airflow sensor, manifold air pressure dont’ mean jack. – Hide quoted text — Show quoted text – >NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which >would be in the intake tract, they said "No, we just replace them", at $105 >each.  I don’t even think there is an intake air temp. sensor on this motor, I >think the computer uses the water temp. to determine cold or hot starting >situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m >thinking of as the "air intake sensor", so it could be either. > I think you meen the air intake temp sensor just above the egr is it ??? > > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > > the plenum. > > > No it is not like th 94 – and i think you are looking at the map sensor > and > > > i am not sure if it does the MAF job too > > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > > the snorkle on the upper plenum. > > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > > Has a mass air flow sensor and where it is ????

Response:

NO, and a dealer confirmed it.  I asked if they ever cleaned the MAF, which would be in the intake tract, they said "No, we just replace them", at $105 each.  I don’t even think there is an intake air temp. sensor on this motor, I think the computer uses the water temp. to determine cold or hot starting situation.  I could be wrong, the Hayne’s manual just refers to the sensor I’m thinking of as the "air intake sensor", so it could be either. – Hide quoted text — Show quoted text – > I think you meen the air intake temp sensor just above the egr is it ??? > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, > right > before the snorkle.  MAP is right behid the snorkle mounted between > "bumps" on > the plenum. > > No it is not like th 94 – and i think you are looking at the map sensor > and > > i am not sure if it does the MAF job too > > > Yes.  If it’s the same design as the 94 (does it have the "black > spider" > > > on top?", it’s in the flexible plastic part of the intake tube, right > by > > > the snorkle on the upper plenum. > > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > > Has a mass air flow sensor and where it is ????

Response:

Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on the plenum. – Hide quoted text — Show quoted text – > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > Has a mass air flow sensor and where it is ????

Response:

I think you meen the air intake temp sensor just above the egr is it ??? – Hide quoted text — Show quoted text – > Nope, my MAP sensor is on the plenum, MAF sensor is in the intake tube, right > before the snorkle.  MAP is right behid the snorkle mounted between "bumps" on > the plenum. > No it is not like th 94 – and i think you are looking at the map sensor and > i am not sure if it does the MAF job too > > Yes.  If it’s the same design as the 94 (does it have the "black spider" > > on top?", it’s in the flexible plastic part of the intake tube, right by > > the snorkle on the upper plenum. > > > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > > > Has a mass air flow sensor and where it is ????

Response:

Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) Has a mass air flow sensor and where it is ????

Response:

Yes.  If it’s the same design as the 94 (does it have the "black spider" on top?", it’s in the flexible plastic part of the intake tube, right by the snorkle on the upper plenum. – Hide quoted text — Show quoted text – > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

No it is not like th 94 – and i think you are looking at the map sensor and i am not sure if it does the MAF job too – Hide quoted text — Show quoted text – > Yes.  If it’s the same design as the 94 (does it have the "black spider" > on top?", it’s in the flexible plastic part of the intake tube, right by > the snorkle on the upper plenum. > Does anybody knows if a 95 GMC Sonoma 4.3 vin W (Vortec) > Has a mass air flow sensor and where it is ????

Response:

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