i have a PFC and the while doing the motor swap i added 1600cc secondaries but i know that wont do anything to the idle. if i barely put my ffot on the gas and hold it at like 800 rpm the motor sounds great but when i let go it tries to idle at like 560 rpm and then dies because the idle is to low. the PFC wont contrlol the idle at all i have it set to 1200 rpm right now but the idle wont go up at all. what does the PFC use to control the idle?

 

Something is not hooked up correctly, or you changed something that has affect idle. Check all wiring, hoses, and PFC values; and if necessary manually adjust the idle up higher.

 

You have a vaccum leak.

 

That would increase the idle as the engine would get more air.