Diesel Place banner

6.2l problems

2876 Views 6 Replies 4 Participants Last post by  sportbug
Hi there.I'm asking anyone who can help.I'm not sure if this is a common problem but I know someone else with a very similar problem.Problem is truck run great cool,but once it warms up when I come to a ferm stop the glow plugs will cycle and the ses light will come on.Once I get going again the ses goes off.Down the highway the ses will sometimes come on causing the torque to unlock then it will shut off torque will relock about 4-6 times then it seem to be okay.I have a 1992 chevy ext.cab 4*4 short box automatic.My buddy has a same truck except it's a longbox and standard,so he does get the torque problems but his ses will go on sometimes down the road & he has the same problem in town with the glow plugs.Open to suggestions.
1 - 7 of 7 Posts
I have no expereince with this setup, but If I were to guess, it is a voltage supply problem.

On the older units when the alternator quit, the plugs would cycle, I would look for a lose battery connection, connection at the starter, and at the alternator.

Heat raises resistance, when the engine heats up it will get worse, that makes sense.

Good luck.
What codes does it set when the SES light comes on?
The codes it sets is just the computer code 12.I had a young mechanic also check it with his decoder and all he was getting was code 12 . when he drove it with his decoder conected he sometimes got the code for the tps (throttle positioning sensor).I've put a new tps on because the old one was very eratic,he adjusted it with his scanning tool.Still the same problems,the batteries were disconected to reset computer.
check your cts (coolant temp sen.)
I thought that the SES light would always set a code. Is this a 1500 truck? Does it have a 4L80E transmission?

Are the ground connections ok? There are 2 or 3 that bolt to a stud on the back passenger side of the intake manifold. When those were off on mine it screwed up a lot of stuff. (transmission wouldn't even shift)

(I have a 93 k1500 ext. cab 6.2)
I've put new temp sensors there's the one on the front of the engine & the one at the back half way down near the starter.I've just replaced my second battery,now it has two new batteries,I've cleaned the grounds on the stut at the back of the engine.I do believe it has something to do with a ground somewhere,because my efforts seem to be improving the problem,but I still get the problem,just not as often.The truck is a 1500 ,but it has the 4L60 tranny.If I use a test light on the ALDL connector F ,the test light itself is enough to ground the solenoid in the tranny,and I can see when the light is on the computer isn't grounding it & when off the computer would be grounding it .Once it's really warmed up,like drove for 100 miles or so the tranny part works fine,but the glow plug cycling will still at times cycle.
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.