Hello all, I have a '92 RS (B4C) that I recently bought. It's a 5.0/5 speed car. Since I bought i've been slowly trying to get it to to run as it should. It's always had a high idle problem so the first i did when I got it home was a major tuner up....plugs, 195 deg. therm, fuel filter, dist cap/rotor and ran some fuel injector cleaner. I cleaned the throttle body and have sprayed carb cleaner at all vacuum connections to check for leaks and there were no change in idle. The fan was wired direct so I got that fixed and changed the coolant temp sensor. Now the car will randomly idle normal, at 800, or stay stuck at 1500 or fluctuate from 800 to 1100. If I restart the engine, it will idle normally but as soon as I load it by putting it in gear it'll begin to adjust and then jump to idling high again.

Any ideas on what this could be, EGR valve or IAC valve? When i pulled the throttle body off I clean it pretty good but didn't really focus on the IAC below it.