1993 'Burb Stalling Problem

[Fryall4]

Heres the pic, looks like it got real hot at some point

[Fryall4]

Is there anything more to resetting the computer then pulling the battery cable for a while? Is there a certain procedure when starting the vehicle ie, idle for a while, raise rpm's? Thanks a lot, Fry-

[2000CAYukon]

Originally Posted by Fryall4

Is there anything more to resetting the computer then pulling the battery cable for a while? Is there a certain procedure when starting the vehicle ie, idle for a while, raise rpm's? Thanks a lot, Fry-

Disconnecting the battery will reset the ECM. Relearning of the fuel trims can take about a week of normal driving.

Hooking up a scan tool to see Sensor values, fuel trims and 02 Sensor activity would help right now.

//2000CAYukon

[Fryall4]

Thanks 2K. My uncle has a Snap-On scanner, we had it hooked up before to see if there were any stored codes which there wasn't. I can try and get together with him again and check on those values. I am about $300 into this now and may just take it into my mechanic. I wanted to avoid that. It is my daily driver and as it is now, I don't even want to drive it, I have kids. Anyway, I may swap out the coil just to test that theory while I am waiting to see when the mechanic can get it into the shop. Anything else come to mind? Fry-

[Fryall4]

Coil is not the problem. Idle still WAY too low, running 250 rpm's in gear, about 400 rpm's in Park. I am at a loss. I am left thinking Coolant temperature sensor, some obscure vacuum leak, computer, or catalytic convertor. Am I wrong? Anyone? Thanks again, Fry-

[2000CAYukon]

Originally Posted by Fryall4

Coil is not the problem. Idle still WAY too low, running 250 rpm's in gear, about 400 rpm's in Park. I am at a loss. I am left thinking Coolant temperature sensor, some obscure vacuum leak, computer, or catalytic convertor. Am I wrong? Anyone? Thanks again, Fry-

A scan tool will show you what the temp sensor is reporting to the ECM. If you unplug the sensor (in the intake manifold near the tstat housing), it will tell the ECM that the engine is running cold and it should increase the idle speed. What happenes if you do this?

Is fuel coming out of both fuel injectors?

Unplug the 02 sensor, remove it and start the engine. If the cat is plugged, it should run a better with the 02 removed. If the cat was plugged, it would not run well at highway speeds either.

Testing the fuel pressure on the TBIs is a pain; however, you need to test the fuel pressure and make sure it is within spec (9 to 13 PSI). Or take it somewhere to be tested.

//2000CAYukon

[Fryall4]

I see 2K, you are a very wise person, thank you. Fuel is coming out of both injectors, and I will check on the O2 sensor asap and the coolant temp sensor today. I am taking it to my mechanic today, and he can test the fuel pressure for me, I will know more in a day or so. Fry-

[Fryall4]

I talked to the mechanic yesterday, he didn't have a lot of time to devote. He said he was leaning towards a computer problem or a transmission pressure switch problem. He was sort of stumped as most of his tests came up negative. He noticed an issue with the IAC valve when hooked to the scanner. He said it was showing activity on one of the coils at idle, which I guess is not supposed to be. I could be mistaken, he was throwing a lot at me, and I tried to remember as much as I could. Anyway, he hasn't called today, but I did tell him yesterday that the truck was of little use to me as it was so he may not have put it high on the priority list for today. Fry-

[bluechevelle]

I had a similar problem with my '94. It ended up being the temp sending unit in front of the throttle body. Doubt it is your problem from what I'V read, but for $11 it's worth a try.

[Fryall4]

I appreciate any help and suggestions Bluechevelle. I haven't heard back from the mechanic yet, so it must not be the best of news whenever that comes. Such is life huh?