on my b16a motor with edelbrock intake and skunk2 TB.... the idle was up and down very erratic until i found a few vaccum leaks, i fixed the vaccum leaks but the idle was still erratic from 1000 rpm to 1500 rpm....now that i replaced the IAC valve with an aftermarket part before i buy the original from honda now the idle is at 2000 rpm steady........ is there any adjustment to the IAC ?

 

Yes there is a idle screw on the Throttle body that can adjust the idle but its not recommended to do that but some have had success bringing the idle down via adjusting the flat head screw on the front of the throttle body. Before this make sure there's not too much tension on the throttle cable itself, what happens is you put the cable on too tight and it holds the throttle plate open very slightly and causes the idle to jump, You can test this by pushing the throttle plate manually from the side where the cable attaches, give it pressure as if your closing the throttle plate, if your idle drops you know the throttle plate is slightly open causing the idle to surge high.