High Racing Idle

[oconnord]

Out of nowhere at a stop light, the sho raced between 2 and 3k at idle in neutral and stayed there. It hasn't come down. Car was running perfectly since a 60k a couple of months ago. Any ideas? I don't know how to pull the codes, but I can try to reset idle. It is not really drivable like this. Thanks

 

[BlackOnBlackATX]

is it actually throwing a CE light? check my signature to learn how to get the codes. if the idle is your only problem then its a vacuum leak somewhere. not entirely easy to trace down but not impossible. let us know if you have any codes.

 

[Ishodu]

Sounds like a Vacume leak check all the hoses and fittings around the intake. Listen to see if you can hear any air being sucked in. Did you replace you intake gaskets?

 

[oconnord]

The car was not showing a check engine light. I reset the idle and cleaned the IAB and restarted the car and the same problem. The IAB was very clean, just like the engine was at the service. The intake gaskets were replaced at the 60K, and like I mentioned it has run great for 2 months. After I returned from the reset, I pulled in the garage and left it running - it was about 2200 rpm. I unplugged the MAF and the idle went down, then I plugged the MAF back in and it stayed down. I'm not sure what this means - whether the MAF had a bad connection - would the MAF cause this kind of engine surging and high idle?

 

[HopefulSHO]

Doubtful. Sounds like a vaccum leak to me too.

 

[sdpatt]

Could be a vacuum leak, TPS or electrical problem internal to the IAB valve. You can't clean that part of the IAB valve.