I have gsr swapped civic and I'm having some problems with the idle. On cold start it will idle between 1500-2000rpm and when warmed up it will usually fluctuate between 1000-2000rpm but sometimes it will stay at 1000rpm which I believe is still considered high. The car has a skunk 2 intake manifold on which means it doesn't have the butterfly valve manifold but is still on a stock p72 ecu, could this be the problem? does it need a tune?

 

IACV, idle air control valve...dirty maybe. I had the same on my gsr swap, but I kept the OEM 2-stage intake, so maybe not....and used a hondata p72. That also helped.

 

How can I diagnose the IACV? I tried the carb cleaner trick to find vacuum leaks and if I spray below the throttle cable area the idle will rise which made me think I have a bad throttle body gasket. However, I'm able to stall the engine by covering the throttle body with my hand, does that mean it is not a vacuum leak problem?

 

It's typical just to take the iacv...and the throttle body off and clean them both. There's no garrantee that'll solve the problem, but they probably need it. Replace gaskets and sensor o-rings.

Unless you installed the manifold and did it then.

Then follow the idle adjusting procedure, timing too.
Another thread that goes along the same lines:

https://honda-tech.com/forums/tech-m...rched-2044651/

 

What is the proper idle adjusting and timing procedure? I'm pretty new to all of this.

 

If you don't have a good manual, get one. Helms has the procedure.