wzdoug

I need some help with verification on my 99 ZX2 idle problem. It revs clear up to 2800 rrpm when it first starts and is slow to come back down. It does the same thing when I put it in gear. When driving around 50 mph / 2000 rpm the rpms will drop by 500 rpm by moving the pedal slightly (I mean VERY slightly) and then return.

I unplugged the IAC and the idle retuned to normal, just a little lower. The CEL came on (I haven't taken it down for a code read yet). The high rpm at the start went away, as did the rpm drop while driving. This is how I want it to run, but it will only do it when the IAC is unplugged. I put an ohm meter on the IAC and got 11.5 ohms. Does this mean the IAC is faulty, or is it something else? I removed the IAC and cleaned it. I blew into the chambers, and neither sealed completely. Is this normal or is it leaking? I don't want to buy an expensive part like this unless I know its the problem. The MAF was recently replaced and I've cleaned the throttle body. Neither of these changed the symptoms.