Cadillac Repair: 1987 eldorado idle, climate control, idle speed control

Question
when i start my car, over half the time it revs up to about anywhere between 1500-2000 RPMs in park, sometimes i'll hit the pedal and it will drop down to the 600-800 range, then i'll drive for awhile and be stopped at a light or something, and the service engine light will come on the engine is revving high again and i'll let off the pedal and it will speed itself up to almost 60 mph, then it drops down in RPMs for no reason at times, what's going on?

Answer
Hi Jason, Sounds like the idle speed control motor gears are starting to bind inside  or the motor is worn out and needs to get replaced and adjusted. Since the check engine like comes on turn the key on and press the off and warmer buttons on the climate control and hold them for 5 seconds or until it goes into diagnostics. Then if you get a EE30 or E30 code that would confirm that the ISC is bad and needs to get replaced. If this is something that you will do yourself then you will need a manual to explain the adjustment otherwise I can give you directions or just take it to your mechanic.

   Let me know if you need anymore help. Bill