High idle but no code set

**viv1610** · 05-09-2011

I've been having an issue with my 2001 GP SE and a high idle. High as in 1500-2000 rpm while in gear and not pressing on the gas pedal. I have also noticed that when it is doing this, that if I press on the brake the tach jumps up 200-300 rpm just as I begin putting pressure on the pedal to slow the car down.
I've have already had to change the front rotors and pads and I have only had the car since March of this year...I've had to change the coolant temp sensor (that set a code) and had thought that would fix the high idle issue...but no luck. The high idle first happened after the code was set, so I thought is was related, but I guess not.

It doesn't do this all the time, but once the high idle starts it continues till the car is shut off and has a chance to sit for a while.

Does anyone have any idea what could be causing this?

**FordMan77** · 05-10-2011

Well, the RPM jump when you hit the brake is most likely the torque converter unlocking. This is normal.

As far as the high idle goes, I'd clean the MAF and IAC (idle air control) valve and see what that gets you. Sounds to me like the IAC is carboned up and is sticking.

I don't recommend brake or carb cleaner being used on the MAF as it is an electronic part. They make cleaner specifically for throttle bodies and MAF's.