'95 T-100 2WD, trouble with warm engine starts

[TazInCT]

I am having a problem with my '95 T-100 and wonder if anyone here has seen this problem or know what the problem may be. My truck has a 3.4L V6 with EFI.

My problem only happens with a warm engine.... cold starts go perfectly everytime. Normally, when starting the truck with a warm engine, I turn the key (without touching the gas pedal), the truck starts and immediately drops down to a normal idle around 800-900RPM. The problem began a few months ago when every now and then, when attemping to start my truck, I would turn the key (without touching the gas pedal) and the truck would start and immediately drop down to an idle of around 300-400 and would eventually (after about 3 or 4 seconds) die out completely. The only way at that point to start the truck is to turn the key, give the gas pedal one good pump while cranking, and the truck would start up fine.... idling normally as it should.

Lately, the problem has been happening more and more regularly. I am now at a point where I can reliable say that it WILL happen everytime I start with a warm engine. I can get the truck running, but it's driving me batty!

Anyone have any ideas? Any help will be greatly appreciated.

[ALWilson]

Howdy,

Can you or have you checked the OBD with a scan reader? This may point to a faulty sensor. Do you get a Check engine light?

Before that I'd check, air filter, vacuum lines, and maybe the fuel filter, sounds as though it running fine when cool because the mixture is enriched when the temp is low, but after it reaches operation temp, the mixture is leaner and thus it stalls unless you open the throtle which sends a signal for more fuel in the mix?

They are complex and self adapting systems, fuel/air/temp/ but from what you'd said, something in the trio is out of balance when the engine warms up. Any performance problems at high speed? Lack of power?

Free advise is worth what you paid for it so please consider this my opinion and not a repair suggestion.

I have the same truck, 97 version and like it alot. How long have you owned yours? Any transmission mysteries? Front end shimmy problems? Sure would appreciated hearing one way or the other.

Good luck

[TazInCT]

I haven't check for codes because I haven't gotten a check engine light. Could there be codes there anyways? I have a reader, but didn't see the point without the light lit.

The truck runs great when it runs.... no lack of power or mileage problems. I hadn't even considered the fuel filter... might be worth a look.

I've had this truck for about 1 1/2 years now & I love the truck. The only problem I've had to date is that it needed a new starter. When I purchased the truck, it was like new with 70K miles on it. It has about 83K now.