i have a 1990 crx dx with 271,000 miles and when its in park the idle goes any where from 1,500 to 500 and gets real annoying i mean its my DD but it still bothers me. Any idea's on what it could be? all i have done is exhaust, headers, cold air intake. Like i said its just my DD but i want it fixed its really annoying me Help would be great!!!

 

That sounds like surging to me... Next time use the search button.

1. Not enough coolant.
2. IACV
3. Kink in the coolant lines from IM through TB.
4. ....
5. Vacumme leak? SP?!?!

So next time search!