TowRig.com - Diesel Discussion and Tow Tech

First off great forum I found it when researching trailer options. I found this section of the forum so I thought I would throw this question out.

I have a 92 Chevy 2500 (6lug) 6.2 diesel and the engine light keeps coming on. It does it no matter if it is warm or cold. But if I rev up the engine it will go off for a minute then come right back on. A friend of mine said that with this engine he thought the engine light only pertained to the transmission. I believed him for awhile (I'm no mechanic) because it would go off if I wined through the gears, but this was before I realized it also went out if I rev the engine in neutral or punch the gas in drive.

I asked the guys at AutoZone if they could test it but they said only if the light stayed on all the time. The guys admitted they had no idea but suggested maybe oil pressure. It has oil and the pressure reads fine on the gages.

The light is on more then not. Any ideas what I can look at? This has been going on for a year now. Several months ago I was hearing a ticking noise coming from the vacuum pump. I parked the truck over the winter (it's a summer work truck) thinking I would replace the pump soon but I have been driving it for a few weeks and it has not made the ticking noise again. I'm thinking the pump was seized up and miracle unseized. So part of me is thinking the warning light was telling me all along I had a vacuum pump going bad, even though it started making noise long after and has stopped making noise.

This truck is city driven at low speeds stopping and going pulling a small landscape trailer with a 3,000 lb GTW. Just pulls mowers around in town so it does not get opened up on the highways.

Sorry for the long post, I just wanted to include as much info as I could to give a clear picture.

Thanks a bunch,
Soupy

What transmission do you have? TH700?

You have a non-electronic engine... and most likely a non-electronic trans - yet the engine light comes on. :confused:

VSS maybe? Fuel filter dirty? Water in fuel?

Maybe you can try reading the trouble code...
http://www.troublecodes.net/GM/

I'm not sure what transmission I have. I think it is electronic controlled. I'm not very mechanically inclined :) . I did check the code using a paper clip. The light came on, paused, then flashed twice. Thought it was weird that is the sample they use on the link you provided. I didn't see the 6.2L diesel on that page.

EDIT: I noticed that all codes start at 13. What does 12 mean? This light does not stay on constant, but is on more then not. I drive short distances. I am assuming the 12 means everything is fine?

The transmission is THM700-R4.

Ok... I got to looking around the engine and it looks like one of the injectors might be leaking. I couldn't see anything coming out but it is gunk up pretty good. It's the driver side closest to firewall. Could this be causing the engine light to come on. It does seem logical since I can make it go off temporally by revving the engine and then letting off the gas peddle. If I drive with normal acceleration the light stays on most of the time.

I guess it's time to take it in to an experienced mechanic. Does anyone have any ideal what I should expect to pay for an injector replacement at a shop?

PM sent.

This may sound stupid, but when mine came on it was the air filter that was causing it. That was on a 85 Suburban 6.2. I have a chasis manual for it at the shop that I kept. I'll have a look in there Monday and see if it says anything there.

Dave

I finally got to look in the Chasis Manual. I could not find anything that said check engine light. I looked in the wiring diagrams, found everything else but that.

So don't know what to tell ya thats additional to what I already posted.

Dave

Do the paper clip thing again.
Insert the clip and then turn the key on.
The light will flash once and then twice, this means that there are no current codes, it should start flashing the stored codes after the initial sequence.
I am suspect that it may be an EGR fault if the truck runs ok.
These were mechanical injection engines with simple controls.

The tranny may be electronic depending on how late a 92 it is.
The 700R4 (4L60) became the 4L60E which is the same as the 700R except it is controled with the ECM instead of the internal governor and throttle pressure cable.

Get the codes pulled up and then we can go from there.