Rough Idle
 

I have a 1990 Gt , really bad idle, when it first started it seemed like a natural cold idle,but it still kept happening after driving all day. What happens is when i pull to a complete stop the idle sticks at 1,200 or 1,500, and once in a while it will come back down to 0 but goes right back up and after its hot it will stay at 2,000.Its really starting to piss me off, Im stuck, i've changed the Air idle control valve thinking that would fix it.but Now im out of ideas.does anyone know? thank you.

Re: Rough Idle
 

Try checking you tps voltage. Should be .97-.99 or around that as long as it's not over 1.0. Also have you adjusted the idle at all?
-Ryan