so just finished my b20 swap, and i start the car up and it slowly climbs up to 3k and keeps going? ive checked double checked all the vacuum lines,cleaned the iavc and double checked everthing else? i cant figure out why its doing it? any ideas?

 

Make sure your throttle is closed 100% (throttle cable may be holding open a bit). Close your throttle set screw on your throttle body. Check how much air is getting through the fast idle control valve (cold start control valve) by blocking the lower port with your finger and see if the idle drops.

If it does, adjust the FICV by removing the rear plate and tightening the set valve position.

 

the throttle is closed, and ill have to check the ficv today.

 

well i still cant figure out the idle problem, i cleaned the iavc and did the fivc? i also replaced the intake manifold gasket because i thought that it had a leak from there.

 

Check for open holes/ports in the intake manifold. (which I'm sure you have already done)
Throttle gasket.
Check the MAP sensor outputs to the ecu?
Check the TPS voltage levels.
Make sure the injectors are compressed against the manifold positions?

If you plug both internal ports (IACV and FICV) of the throttle body, does the idle drop / possibly killing the engine? (try this with your fingers while the engine is running.)

I'm running out of suggestions