Ok so i have a B18a that idles at about 2500-3000 RPMS. I have double and triple checked for vacuum leaks NONE ARE PRESENT. I removed and cleaned both the IACV and the FITV. I have also adjusted and played with the tps sensor. No change in idle. The throttle cable is adjusted properly and has slack in it and the throttle plate is not stuck partially open. I removed the IACV a second time and jumped the terminals to make sure the plunger moves. It makes a clicking noise and moves a little less than a quarter inch when jumped directly with 12V straight from the battery. While running at 2500 rpms....if i unplug the IACV the idle will go down to about 1200 cold (which is normal ) but it will hunt for idle. I think it might be a bad IACV but im not positive....help anyone please?

 

while its running , take off your airboot and stick your finger over the bottom hole inside the throttle body. that is the fitv supply hole , if the idle drops to normal then the fitv is leaking/bad which wont be fixed by cleaning. i know happened to me if fixed it by pushing gasket maker into the hole while it was running till it plugged the valve , fixed that problem. later on i just bought one of those power throttle bodys that has a bypass instead of a fitv. the computer still raises the idle up to about 1500 when cold. please readjust the tps with a voltmeter it has no affect on the idle whatsoever and thats a quick and easy way to toss a motor.

 

Have you tried a new pcv valve? Take your breather tube from your valve cover out of the intake side, and plug it on the valve cover side. So basically just plug the breather that goes into the valve cover. If your idle drops, then you could need a new pcv valve as that's part of the breather system as well.