I have a 1990 Integra RS. When I start the car when its cold, it idles up to about 2300 rpm and sometimes fluctuates up and down from 800 to 2300.

After about 3-4 minutes, it stops and idles normal, but slightly, and I mean slightly rough.

Any idea what this is? I am guessing a sensor. Maybe TPS or map. If you know what it is please tell me how to check it .

THANKS...............

 

sticky fast idle thermo valve.

 

how can it be fixed, my car does the same thing? i thought it was a vacum leak and could not find it.

 

 

anybody!

 

usually happens bcos of 2 reasons.

1. IACV dirty/clogged - clean it
2. you did a throttle body coolant bypass the wrong way (sealing both ends of the coolant lines instead of joining them) - u need to join the lines and make sure coolant flows right thru.

 

as somebody sayd above, check your fitv. take it out and shake it, if it rattles, then it needs to be fixed. to fix it take it apart and screw the little white screw back in.

 

what is fitv

and how do i check the coolant bypass>?