Well, I was going to post this in off topic... but I figured it wouldnt be a huge sin to post here..

Anyway, my church has a 92 chevy 2500 TBI 350 truck, that is stalling when they touch the pedal. It starts ok, idles sorta ok, and is abruptly got worse after it showed this problem a few days ago. They told me that it basically is flooding itself to death, as they have to hold the pedal down to start it again after it stalls. They also said its a very low chance of being a spark problem.

I am looking for some things to check if I go up there today or tomorrow, I am thinking right now its a failing fuel pump, as I cant really pin this problem on any one sensor. If it was a sensor issue, i think the iac and MAP sensors would be the biggest culprits.

I really ask you guys to think out loud here so I dont spend 5 hours in the sub zero temperatures not fixing anything on this truck.

If the vehicle idles, I would think the IAC should be OK. But you could remove it and check for carbon build up and desludge it if necessary. Fuel pressure is also a good place to start. Possibly the TPS could be going since it seems to do it whenever throtte is moved? You can test that pretty quickly with a meter.

If the vehicle is flooding I can almost bet you it's your coolant temp sensor on the intake manifold. This little jewel sends a signal to the ECM telling it how cold or hot the engine is thus allowing the ecm to determine how much fuel to give the engine. Part will cost you about 15 bucks and takes just a few min to install! Let me know if that does it!
Jeremy

In cold weather when the engine is cold the fuel sprayed does not evaporate as fast. My guess would be it is not spraying very well. More like it is spitting. So the TB plate has a lot of raw fuel sitting on it and when you blip the throttle a large amount of raw gas falls into the engine and floods it.
The TB and the injector might need to be cleaned out or the fuel pump or pressure regulator are going bad.
Another thing to check is the fuel filter. If you recently filled up at a gas station that recently had it's tanks filled you could have picked up some sediment and it is clogging the fuel filter. This will reduce your fuel pressure and cause the injector to spit instead of spray.

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[This message has been edited by Oreif (edited 01-22-2008).]

quote Originally posted by 1984SE2M4: If the vehicle is flooding I can almost bet you it's your coolant temp sensor on the intake manifold. This little jewel sends a signal to the ECM telling it how cold or hot the engine is thus allowing the ecm to determine how much fuel to give the engine. Part will cost you about 15 bucks and takes just a few min to install! Let me know if that does it! Jeremy

I considered this as it is one of the open loop fueling methods it looks at alot, but I wasnt really sure that it would idle with this giving a random temperature.

I will look over the fueling system as much as I can, and just hope it is regulating it properly. I really dont want it to be a fuel pump...