93 Grand am high idle with AC/Heating

[zebu18]

Hi All,

I am having a problem with my 4cyl 2.3 L SOHC 1993 Grand am. For the last couple months, whenever I turn on the AC or the heat the engine starts to idle high, I feel pressure on the gas pedal, and it almost feel like the car is going to take off by itself if that makes sense. I bought the car a year and a half ago and it now has just over 112,000 miles on it and I'm not sure the last time it had a tune-up. Could that be the problem?

Thanks for reading!

[richtazz]

Could be a tune-up issue, but I'd look at the IAC valve. Its a small stepper motor on the throttle body that regulates air entering the motor at idle or part throttle. It adjusts incoming air supply in accordance with engine load, and sounds like where your problem lies. You can take it off and clean it, as it is common to get gummed up by fuel deposits. Just be careful not to move the pintle too much while cleaning it, or you can mess up it's calibration. While you have it out, spray some cleaner up in the bore in the throttle body where the IAC rides, as it gets gummy too.

[zebu18]

Thanks! Is this something you would say I could do myself (not a great mechanic) or better off taking it somewhere? Any idea how much it would cost either way?

Thanks again.