engine runs rough/stalls out during the warm up phase. usually drives fine at temp.

1995 GMC 1500 4x4 5.7L automatic.

NO CODES, NO ck engine light.

I have changed plugs, wires, coil, dist cap, rotor and distributor module. MAP sensor.

I notice this problem to occur when COLD outside(under 60 degrees)-despite being parked in a dry garage. Car starts right up, you must give it steady gas until it is warmed up, even then I experience some of the following. More often than not, once it comes up to temperature, you can drive it. if you drive it when cold, it is sluggish, revs on its own, lunges, stalls at stop light unless you throw the automatic in neutral. once up to temp-drives fine.

any thoughts?

looking forward to your suggestions.

EAA

 

hey. my wifes truck did the same thing. hers is a 87 dodge dakota. ended up being the choke. hope that might fix it.

 

sounds like the iac valve to me?????????

 

Not REAL sure about gm products, but on Dodge, if your battery is weak, the automatic choke won't work properly. Something to do with the computer. Might look at that. Good luck.

 

Hello everybody...I'm new here but am having this same problem...did anyone solve it...and what is an IAC valve?

Thanks,

Barry

 

possibly coolant sensor..... computer might be fooled about temp and getting wrong fuel mixture

 

I agree with alineman...I think the computer is being fooled thinking the truck is at the wrong temp for warm up. I had one go out on a 454SS truck I had and it left me stranded in Daytona Beach (there are alot worse places to be stranded trust me). I think they are under $20. I was mad when we towed the truck all the way back home for such a cheap part!

 

Hey alineman we just responded to a 2 1/2 year old thread...they probably got it fixed by now. Oh well I still agree with your diagnosis. Later!

 

Still good info guys. I'm glad you resurrected this oldie cuz it kinda gave me a new angle to look at. Mine's running a little rough and it's probably cap/rotor/dirty tbi but if it's not maybe a new stat would help. So many of the problems we have already been covered so it's good to read thru the older solutions. Ya never know what you might find

 

I figured I would try to help someone since I'm at a loss for my problem