92 3.1L Cranks great, but won't start

[Fry]

I have a 1992 Chevy Lumina with the 3.1L engine.
I have had some problems with keeping it running at low RPMs for a while now. Some days it runs like a dream. Others it will stall when I come to a stop. In the past I have remedied the situation by keeping on the gas at stops and riding the brake at lower speeds while gassing it.

Well, I'm at work right now, and the darn thing won't start. It cranks perfectly. (New starter) Not even a sputter. It ran beautifully on the way to work this morning. How can I diagnose the problem? Given its behavior over the last few months, does this sound like a sensor issue, something with a sticky valve, or a fuel pump problem? The only other time this happened, about 4 days ago, the car started after 3 tries. No such luck today. Any suggestions or help is greatly appreciated.

-Fry

[xjoeharperx]

you might have a problem with idle air control valve , and possibly the egr valve is stuck open. as far as not starting, check to see if you are getting a signal from the crankshaft position sensor and the camshaft position sensor. PM me and tell me what you get

[JERKY420]

If all else fails test your injectors the symptoms sound familiar to an injector problem I had.

[xjoeharperx]

The computer is bad. Any time you have an intermittent problem that keeps it from running and then just goes away is a strong sign that the comuter is bad...There is a bad capacitor in the power control circuit. when the capacitor malfunctions the computer sees that the car is running wide open throttle and gives maximum spark advance and maximum fuel delivery. any sensor that runs off of reference voltage is affectecd by the computer going haywire...

[Fry]

Is that.. hmm, what's the word I'm looking for?

Ahh, yes. Expensive?

[xjoeharperx]

It shouldnt cost over $150.. know its not cheap but its workable...you can also try a used computer if you dare...sometimes they work sometimes they dont...and once you buy it its yours...here is a link. http://www.partsamerica.com/PartDeta...pe=248&PTSet=A

here is another.. http://www.autozone.com/servlet/UiBr...INE&PageSync=6

the second one from autozone is 73 dollars...not bad...

[Jeffi]

I have the same problem on a 93 Lumina APV 3.1L. No spark and NO gas at the injectors. Checked the pickup coil and coil and checked all connections at the distributor. Here's the thing - it worked fine for quite a while then back to the old behaviour; won't start if warm but will start up fine a couple of hours later, sometimes stalls at idle (usually at a busy intersection). Let me know if the computer swap turns out OK! I'm gonna take out the distributor and clean everthing up and try again

[Jeremy-WI]

ignition control module can be an intermittant problem too

If you want to do diagnostics, try www.alldatadiy.com for $24.95/year/one vehicle you can have access to a web version of the GM service manual and Gm part prices. I hate to sound like a infomercial, but its pretty handy when you need it

[Fry]

The mechanic said it was a computer problem after he had it for 3 days. He also recommended I take it to a dealer to confirm his diagnosis. Since that will run $50 just for them to hook it up, I'm going to take a trip to a junkyard and find a brand new used computer and do a swap. I will let you know how it goes. It may be a while though. The weather has been nasty and I don't know anyone that enjoys working on cars in the freezing cold bustin' up their knuckles. Then again, it is just the computer.

[Jeffi]

Originally Posted by xjoeharperx

you might have a problem with idle air control valve , and possibly the egr valve is stuck open. as far as not starting, check to see if you are getting a signal from the crankshaft position sensor and the camshaft position sensor. PM me and tell me what you get

I'm pretty sure the 3.1L has neither a crankshaft nor a camshaft position sensor. It does have a knock sensor?!?!?!

[JERKY420]

fyi the 3.1 does have a crankshaft positioning sensor it should be on the backside of the engine next to the tranny.

[Jeremy-WI]

92's have a crank position sensor, wires go from it directly to the ICM. Wonder if part of the problem is the TCC staying engaged?

[michelq]

FRY look at right side of radiator there is sensor remove plug wire and see how the car run

[xjoeharperx]

Jeffi. check for power to the ecu. you might have a blown fuse. no spark or injector power sounds like total ecm failure...check all the fuses and power leads..

[Jeffi]

i keep thinking computer then the van starts up and runs fine for a while. When it won't start, it cranks great just like Fry's but no spark and no fuel. I've been holding onto a lead when the car changes its mind. Got a good jolt and could see pulses of gas from the injectors. How likely is it that the ignition module is heating up and shorting due to no heat dissipation in the distributor (ie. no installation grease)??