idle speed control

any one no where the idle speed control is at in a 1990 ceclipse thanks

I had a problem with high idle when I bought my car. It ended up being my throttle body all gunked up with deposits from the blow by that was recirculated into the intake before the turbo. A tooth brush and fuel injector cleaner scrubbed it up nice and clean, and removing the hose that came off the valve cover (replacing it with a small filter) seemed to fix the issue. I also wanted quicker throttle closure and added a small spring on the throttle body to assist it in closing. This made my RPMs drop quicker between shifts and made shifting faster.

What kind of problems is your car experiencing ?

On the throttle body. Can't miss it. It's a roundish cylinder-shaped thing.

my car idles up and down by it selfe