I've got a 1998 Cadillac Deville. The car runs well but randomly the outer shoots are way up and get stuck at 2400 RPM. I cleaned the throttle body, checked the throttle cabel, disconnected cruise, replaced IAC and TPS. Just can't fugure it out.
If it's idling that high, something is really sticking there. You might check your throttle cable because it's an old one. It's not the modern one that has a drive-by wire with no throttle cable. Check the throttle cable as it could be sticking. The cable could also be frayed.
You can lubricate the cable just like a motorcycle cable. Get a spray lubrication and spray the lubrication inside the cable to keep it from sticking. You'll want to make sure that the throttle itself isn't worn. You said you cleaned it but sometimes when they get old, they warp and the throttle will stick in open positions. In that case, you're going to have to buy a new throttle assembly. They cost a whole bunch of money so you might go to a junkyard for something like that. You may want to have a mechanic inspect your high engine idle in order to diagnose the problem and make the correct repairs.
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