Working on my brothers 2003 gp 3800 and having a issue when the engine gets up too operating temp (closed loop) the idle goes up too about 2000 rpm weather in park or in gear. I have checked for vacuum leaks and confirmed the throttle body is closing and not sticking. Odd thing that happens is if you shut off the engine and restart the idle will go back to normal. He recently changed the front O2 a new TPS and another MAF. Only code coming up is with the transmission. Any ideas would be appreciated and thanks.

 

You got 2 of the 3 sensors on the throttle. Have you checked the IAC?

 

IAC valve clogs up in these engines pretty easily..

 

I second that IAC check.

 

Well I picked up a new IAC (Borg Warner Division) got a deal from a friend $27.00 . Got home loosed up torx screw #1 and snap torx screw #2 snap. I tried too drill the old screws out but didn't work so well, cant drill a straight hole for the life of me. I was carboned up enough to create a bad seal . Have to get another throttle body not happy with screws I have holding it in place. Thanks for the suggestions Jason B, Wht02monte and ChiBiBlackSheep I do appreciate the quick reply's

 

If you need another TB, I have an extra lying around.

Let me know if you can't find something cheap and local.

 

I ruined those screws trying to get them out... I was able to get a small pair of vice grips on the screws and get them out that way.. It took forever but it worked..

EDIT: Oh you snapped the heads off.. Well damn.

 

Latest update: Had a friend with a scanner check everything over including the wiring and conclusion was the PCM might get going out. Being the nice brother I pulled the PCM out of my Monte and sent it back to the Maniac to be de-programed and set back to factory settings. As of now the car is running fine the idle is normal and shifting seems to be fixed (fingers crossed). Haven't tried to start my Monte but hope I don't need to get another PCM since I bypassed about everything. I appreciate the help from all that replied and a Big shout out to Jason (the Maniac) for the programing and super fast turn around.

 

Glad that it might be resolved!

 

No problem on the help and turn around. I do my best to get that PCM out the next mail day as for many people, they are without a vehicle when they send a PCM.

Hope all the issues are now finally resolved.