OK, now I'm running a turbo LS/Vtec and i've got surging in my idle. It will surge at any RPM for 500 RPM. Example, at idle it will surge from 1000 to 500, if I hold the throttle at 3000 then it will surge between 2500 and 3000. I've been messing with the idle control screw and cannot get it to stop. When I unplug the IACV it dies right away. I've cleaned the IACV and still no good. Is there an electrical test that can be done on the IACV to make sure that it is operational? Also, about how many turns from fully in should the set screw be? Also assuming that a vacume leak could be causing this, but I cannot find a leak anywhere. This is how I have my vacume lines setup, OBX Intake manifold so two acc. vacume lines. BOV and Wastegate going to same port on intake, FPR and GM 3 Bar on same Intake port. Also, I am running an Apexi Power FC.

 

sounds like you have a vaccum leak somewhere. find that and you will fix the surge

 

But is the car supposed to die when the IACV is unpluged?

 

Man this sucks, theres not that much to the vacuum on this car. all of my connections are good, the manifold is tight, i just bled the coolant. WTF!!

 

bump for a poor tired guy.