93 GMC Safari Rough Idle
Question:
Hi. I have a 93 GMC safari with 165k miles. It runs rough and smells like sulfur when it idles. After taking it to the dealer a few times without much success (He said it was just old) he finally said it needed a new CPI injector unit. Wanted $1000 to put one on. I got a good deal on a new CPI unit and put it on myself. It did not cure the problem. Put on new wires, plugs and have checked the EGR valve. Everything seems fine, but it just won’t idle without loping. What else should I check? Thanks.
Response:
If it’s misfiring at idle, it’s quite possibly due to an ignition problem. Could be a problem with the pickup, ignition coil, etc. — Robert Hancock Saskatoon, SK, Canada Home Page: http://www.roberthancock.com/
– Hide quoted text — Show quoted text -> Hi. I have a 93 GMC safari with 165k miles. It runs rough and smells > like sulfur when it idles. After taking it to the dealer a few times > without much success (He said it was just old) he finally said it > needed a new CPI injector unit. Wanted $1000 to put one on. > I got a good deal on a new CPI unit and put it on myself. It did not > cure the problem. Put on new wires, plugs and have checked the EGR > valve. Everything seems fine, but it just won’t idle without loping. > What else should I check? Thanks.
Response:
O2 Sensor?
– Hide quoted text — Show quoted text -> Hi. I have a 93 GMC safari with 165k miles. It runs rough and smells > like sulfur when it idles. After taking it to the dealer a few times > without much success (He said it was just old) he finally said it > needed a new CPI injector unit. Wanted $1000 to put one on. > I got a good deal on a new CPI unit and put it on myself. It did not > cure the problem. Put on new wires, plugs and have checked the EGR > valve. Everything seems fine, but it just won’t idle without loping. > What else should I check? Thanks.
Response:
ck your cat. converter
– Hide quoted text — Show quoted text -> Hi. I have a 93 GMC safari with 165k miles. It runs rough and smells > like sulfur when it idles. After taking it to the dealer a few times > without much success (He said it was just old) he finally said it > needed a new CPI injector unit. Wanted $1000 to put one on. > I got a good deal on a new CPI unit and put it on myself. It did not > cure the problem. Put on new wires, plugs and have checked the EGR > valve. Everything seems fine, but it just won’t idle without loping. > What else should I check? Thanks.
Response:
>ck your cat. converter > Hi. I have a 93 GMC safari with 165k miles. It runs rough and smells > like sulfur when it idles. After taking it to the dealer a few times > without much success (He said it was just old) he finally said it > needed a new CPI injector unit. Wanted $1000 to put one on. > I got a good deal on a new CPI unit and put it on myself. It did not > cure the problem. Put on new wires, plugs and have checked the EGR > valve. Everything seems fine, but it just won’t idle without loping. > What else should I check? Thanks.
Cat is ok and the thing passes Georgia emissions inspection rough idle and all.
Response:
By the way, when I changed the plugs I noticed one side of the engine had black deposits on the plugs (not severe) the other side had brown. That was before I changed the CPI however. – Hide quoted text — Show quoted text – >ck your cat. converter > Hi. I have a 93 GMC safari with 165k miles. It runs rough and smells > like sulfur when it idles. After taking it to the dealer a few times > without much success (He said it was just old) he finally said it > needed a new CPI injector unit. Wanted $1000 to put one on. > I got a good deal on a new CPI unit and put it on myself. It did not > cure the problem. Put on new wires, plugs and have checked the EGR > valve. Everything seems fine, but it just won’t idle without loping. > What else should I check? Thanks.
Response:
Do you get blue smoke on startup? May be that the plugs on one side are fouling from the oil and causing a rough idle. Oil leakage into the cylinders overnight is a common problem, I think the valve seals harden and fail to seal after a while… – Hide quoted text — Show quoted text – > By the way, when I changed the plugs I noticed one side of the engine > had black deposits on the plugs (not severe) the other side had brown. > That was before I changed the CPI however. >ck your cat. converter >>Hi. I have a 93 GMC safari with 165k miles. It runs rough and smells >>like sulfur when it idles. After taking it to the dealer a few times >>without much success (He said it was just old) he finally said it >>needed a new CPI injector unit. Wanted $1000 to put one on. >> I got a good deal on a new CPI unit and put it on myself. It did not >>cure the problem. Put on new wires, plugs and have checked the EGR >>valve. Everything seems fine, but it just won’t idle without loping. >>What else should I check? Thanks.
