2000 Grand AM idles high

[frizzm]

Hello,
My Grand Am has started idling high. Usually this starts after I have been driving for a while (maybe for 20mins). If I brake to a stop the rpms go to about 1.5k. I have to hold down the brake really hard to keep the car from moving forward. If I shift into park it idles even higher. If I turn my car off then back on again the problem goes away (for a little while). Ive already tried replacing the TPS but it didnt help. Any suggestions as to what could be causing this problem.

[Slade901]

More than likely the problem is your IAC (Idle Air Control solenoid). It is next to the TPS. The IAC is a solenoid with some spring on it. You can try removing the IAC and clean it with a carb cleaner and clean the spot where the IAC goes in the throttle body. Cleaning the IAC should fix that problem but if the IAC is really bad and not fixed by cleaning it then just replace the IAC.

[lokeefe]

Originally Posted by frizzm

Hello,
My Grand Am has started idling high. Usually this starts after I have been driving for a while (maybe for 20mins). If I brake to a stop the rpms go to about 1.5k. I have to hold down the brake really hard to keep the car from moving forward. If I shift into park it idles even higher. If I turn my car off then back on again the problem goes away (for a little while). Ive already tried replacing the TPS but it didnt help. Any suggestions as to what could be causing this problem.

I have the same car with the same problem. Just wondering if you've resolved it....? I have the Chilton manual so I've read all the things that you can try, but I'm not a mechanic and would like to try to minimize how much I pick at my car.

[Ridenour]

Originally Posted by Slade901

More than likely the problem is your IAC (Idle Air Control solenoid). It is next to the TPS. The IAC is a solenoid with some spring on it. You can try removing the IAC and clean it with a carb cleaner and clean the spot where the IAC goes in the throttle body. Cleaning the IAC should fix that problem but if the IAC is really bad and not fixed by cleaning it then just replace the IAC.

I wouldn't clean the IAC motor with carb cleaner. It's known to be too harsh. Buy a spray can of throttle body cleaner instead. Clean just the spindle end of the IAC (avoid spraying it down into the motor). Clean the living hell out of the throttle body and IAC motor cavity / intake. Lift your throttle plate and stuff some paper towels underneath it to catch the cleaner, and hose the shit out of the cavity from above, and the throttle body. You'll probably need to do it and wipe several times.

Aside from the IAC or TPS, my guesses would be MAF or maybe a vaccuum leak. But you said you replaced the TPS, so if the cleaning doesn't fix it, I would try swapping out your MAF.