GMC diesel start up problems
Question:
I have a 1982 GMC Gruman step van with a 6.2L motor. It always started up cold fine, but had a little trouble starting warm. Now it wont start at all though. I can’t hear the ticking sound for the glow plugs. I replaced the glow plug relay, but that made no differance. I live in Rhode Island, and temp is very cold outside but this problem starten in November when temp was between 40 and 50 outside. I cannot afford to tow it to be looked at and can’t get anyone to come over here to check it out. Any advice would be greatly appreciated. Thanks, Dave
Response:
pull your glow plugs and check them. Test the resistance from the terminal end to the element end. It should read a certain measurement in ohms. I can’t recall what it needs to read, but, basically, you canuse an analog style and if the needle moves (pegs), then it’s good. If the needle doesn’t move, then it’s scrap. Find out what the Ohm reading needs to be before testing, though. Your local dealer should be able to tell you, or maybe find a place on-line. Snowman
– Hide quoted text — Show quoted text -> I have a 1982 GMC Gruman step van with a 6.2L motor. It always started up > cold fine, but had a little trouble starting warm. Now it wont start at all > though. I can’t hear the ticking sound for the glow plugs. I replaced the > glow plug relay, but that made no differance. I live in Rhode Island, and > temp is very cold outside but this problem starten in November when temp > was between 40 and 50 outside. I cannot afford to tow it to be looked at > and can’t get anyone to come over here to check it out. Any advice would be > greatly appreciated. > Thanks, > Dave
Response:
I’m going to assume that your glow plug warming sequence and dash indicator light come on and go off normally and that the charging system is strong providing your usual cranking speeds. Not a slow crank. Slow or weak cranking will not get the compression needed to start the diesel. If cranking is slow… Cleaning the battery terminals, and other starting system cable/wires will help. I’ve found I had to do this every six months or end up doing it some morning when I’m late for work… Oxidation seemed to bite me in the A$S more than once the first couple years I owned it. Testing glow plugs is like testing a light bulb or fuse. No continuity if the element is burned. One or two failed glow plugs will still let a 6.2 start, all other things being normal. Strong batteries, strong cranking. Of course being on the west coast I’ve not experienced below low 30s and have used anti gel fuel conditioner only once. So temps may impede starting. Do not use conventional starting fluid in a diesel. A can of wd-40 believe it will substitute. Only try it a couple of times though. Several seconds of spray down the intake… The 6.2 uses a fuel lift pump like a regular chevy. Got fuel? You didn’t run the tank dry? I’ve got dual tanks. One ran dry and caused a vapor lock in the fuel system. Damn hard to get started again. Had to have a show go over it. Signs of a failing fuel injector pump are hard starting prior to the failure of the pump. Good luck. Jeff – Hide quoted text — Show quoted text – > I have a 1982 GMC Gruman step van with a 6.2L motor. It always started up > cold fine, but had a little trouble starting warm. Now it wont start at all > though. I can’t hear the ticking sound for the glow plugs. I replaced the > glow plug relay, but that made no differance. I live in Rhode Island, and > temp is very cold outside but this problem starten in November when temp > was between 40 and 50 outside. I cannot afford to tow it to be looked at > and can’t get anyone to come over here to check it out. Any advice would be > greatly appreciated. > Thanks, > Dave
Response:
Nope Jeff, my indicator lights are not working right, but I have new glow plugs and a new glow plug relay installed. I have two brand new batteries in it also. I am wondering about electrical issues like a fused link or another relay. Since My truck is a GMC/Grumman Olsen I am having trouble finding a repair manual on it too. TY for reply, Dave – Hide quoted text — Show quoted text -> I’m going to assume that your glow plug warming sequence and > dash indicator light come on and go off normally and that the charging > system is strong providing your usual cranking speeds. Not a slow > crank. Slow or weak cranking will not get the > compression needed to start the diesel.
Response:
Do you have the G P relay that looks like an old starter solenoid on mounted on the firewall? If not, if its the gp relay with the molex connector I believe there is a temp. sensor on the head, rear, drivers side. Check wires for corrosion, good grounds etc. I’ll have to review the shop manual tonight. Obviously I’m not a trained mechanic. Temps are *COLD* there! just looked at the weather for JFK. Try the block warmer for a few hours. I’m thinking the temp sensor in the circuit… J – Hide quoted text — Show quoted text – > Nope Jeff, my indicator lights are not working right, but I have new glow > plugs and a new glow plug relay installed. I have two brand new batteries > in it also. I am wondering about electrical issues like a fused link or > another relay. Since My truck is a GMC/Grumman Olsen I am having trouble > finding a repair manual on it too. > TY for reply, > Dave > I’m going to assume that your glow plug warming sequence and > dash indicator light come on and go off normally and that the charging > system is strong providing your usual cranking speeds. Not a slow > crank. Slow or weak cranking will not get the > compression needed to start the diesel.
