Automotive Forums

Hi, I am at a my wits end on getting my 92 Burb running at idle again! It died at a stop sign a few weeks ago and I have been through alot trying to get it running again! The 5.7L TBI engine will start fine when cold but as soon as it warms up and idles down will not stay running! I have changed or checked several items including the IAC,TPS,MAP,New Fuel Pump and filter and Relay,New throttle Body kit including regulator,New EGR valve,New Pickup Coil,Checked Ignition module at parts store,new O2 sensor,etc. I am at my wits end! Cant find a vaccum leak anywhere. Vehicle will run fine at anything but complete idle and does not miss at all. When it dies it shutters just a little for a second then dies. The fuel flow at anything but idle is good and the injector spray is consistent. I am next thinking about changing the ECM but would rather not as no codes are being presented at any time. I thought we had found the problem today when we changed the pickup coil and found it to be corroded and melted a little! Vehicle still died after warm up though and would not restart! Please help me with a solution! Thanks,addjdd  

If it runs fine when it's cold, then rough when it's hot, it's proably the coolant temp sensor.  

Thanks for the reply dhjenkins! I changed that yesterday to no avail! Doesnt run rough when hot just dies when it gets to idle after warming! Cannot restart until cold again! Running way to lean for some reason??  

Is the ECM mounted in the engine compartment?  If so, get a can of computer duster (compressed air in a can), turn it upside down and spray the ECM and see if that clears it up - if so, there's the problem.  Another check would be to also try hooking up a DVOM to the IAC circuit to see if the ECM is controlling it.  

It's possible the TBI injectors aren't functioning properly, or the reluctor/magnet in the distributor is bad.

You sound like you really want to fix this yourself, so you might invest a little money in an old OBDI scanner to actually "see" inside your engine.  Fuel trim readings and IAC counts are what you should pay attention to.  

dhjenkins, thanks again for your help! The ECM is located under the glovebox! I have had it out to examine and saw no extreme dust when doing that. Can you tell me more about the reluctor/magnet in the distributor? Would it not inhibit proper running at higher RPM's also if it was bad? My motor would only not idle due to not enough fuel from injectors! I may have stumbled across the fix yesterday as the vehicle is running now! I was still using the same old gas that was in the tank when I added the 2 bottles of injector cleaner a month ago! I wondered if the cleaner was having an adverse effect on the O2 sensor and causing the motor to run lean? I changed the fuel out and filled the tank with new and motor has ran since yesterday OK! I am keeping my fingers crossed that this may have helped? Regards, addjdd  

It really could of been the injector cleaner,Any fuel additive will have an affect on the ox sensors, I never suggest additive to fuel. What I have seen lately in the shop is really bad gas going around, seems to happen around spring time every year.  

Thought I had the problem wipped on my last post but guess what, the Burb died again today and wouldnt start after running 3 blocks! I drove it all last week with only some minor hesitations taking off at stops! I drove it around our neighborhood this morning and ran fine, but when we were headed to an auction 2 hrs later it died at a corner 3 blocks from home! Anyone have any other clues before I take it to a service man? Thanks, addjdd