95 GTP Idles rough and high RPM until warm

[Blue Dog]

When I first start my 95 GP GTP it runs rough and the Idle goes up at a high rpm and then it shuts down,It will do this over an over again until it warms up.Anyone have any idea what might be the problem. Thx,Blue Dog

[fouch04]

my 95 gtp has 3.4L engine and i am having the exact same problems. My cousin is a mechanic and is trying to figure it out can u email me at [email protected] if u find the code number or the problem. We tried changin a few sensor like the low idle so far no change but if i find the problem i will repost.

[richtazz]

you have one of two problems, either your egr valve is stuck open, allowing too much air into engine when cold, causing it to idle high and run rough due to the too lean mixture when cold, or you have a bad IAC motor, which regulates and adjusts fuel mixture when the engine is cold, similar to a choke on a carburetor

[twstice]

I had this exact same problem with the exact same car (95 grand prix gtp) ....the problem with mine was intake gaskets. its real easy to check if they leak. Just take the lil black cover off that covers the injectors, start the engine, and spray some carburetor cleaner (or something like that) if they leak the engine rpm's should fluctuate when u spray the carb cleaner

[IH8RICE]

definatly a good place to start is with the gasket, my uncle whos been a mechanic his whole life didnt think thats what was causing the problem but after doing the intake and plenum gaskets it idles fine. that should do the trick. i have a 1995 GTP and ive replaced mine twice seems like these 3.4 engines have this common problem.

[richtazz]

ah, if it's a 3.4, then I agree that the intake gasket is probably the cause.

[psycho1]

I have an '95 GTP 3.4 V6 and I've replace the IAC motor, PCV Valve, checked/cleaned all the the sensors and the EGR valve and I'm still having the same problem. Has anyone else tried the intake gasket and if so did you have any luck with it solving the rough idle problem or are there any other suggetions out there? Cuz this is really starting to drive me nuts!!

Thanks,