I recently installed a Skunk2 manifold onto my B18C along with an AEM fuel rail (broke lots of bolts taking the old one off) and a B&M fuel pressure gauge. I also bypassed the coolant connections at the bottom of the TB as it never gets near freezing here. Ever since the install, my idle sits at around 2000 RPM. When I removed the OE intake manifold, 99% of the gasket stuck to the head so I spent the better part of 2 hours peeling it off then getting the small bits with a razor. Cleaned up the old TB gasket and mating surface in the same way and used new gaskets in both places. No detectable leaks at any of those mating surfaces. I also replaced the small "8" shaped o-ring in the IACV when I swapped it over to the new intake manifold.

I've double checked vacuum connections (much simplified due to the removal of the IAB). I've yanked the vac line to the FPR and the vac line to the EVAP purge solenoid one at a time and the idle goes even higher with them disconnected. Also, checked the idle adjustment screw at the TB and it's 1/4 turn from being all the way tight -- the idle raises even higher in direct proportion to me loosening it.

I just replaced the stock throttle cable with a Type R unit so it's routed the "correct" way and replaced the TB pulley with that from an LS. No dice. It idles high even with the throttle cable completely disconnected.

One strange thing I've noticed is that it will idle fairly normally after it has cooled down a bit, but not to thepoint of being completely cold. If I drive it for a while then park it for 30 minutes or so, it starts up and idles normally and only idles high once it again reaches full operating termperature. Lastly, fuel pressure (courtesy of the new gauge) sits at 39psi at idle.

Any ideas as to what to check? Thanks!

 

Bump for a cool guy