Originally Posted by
B16a2VTIguy
Well, i replaced the o2 sensor with a new one and the CEL light has disappeared now.
As it idles fine when cold, i thought that would have solved it at first.....but it hasnt, as soon as it had warmed up it started hunting again.
I then borrowed a friends idle control valve off his car, and it still does the same thing, i also checked the pins where the correct way round in the plug (they were the wrong way, so fixed that)
I then removed the throttle body, and cleaned all the vaccum channels etc out, again didnt solve the problem.
The flat headed screw on the intake manifold (IACV screw??) has been moved from STD position when it was turboed, a friend says that has a affect on the TPS, as it reads voltage from the TPS to start using the idle control valve.
Im gonna check the voltages tomorrow, and make double sure all vaccum leads are not leaking tomorrow.
If you used a known good IACV and the problem persists, the problem has to exist in the wiring or ECU. Is it still throwing a code for IACV? Have you tried another known good ECU?
Try spraying around the manifold and vacuum connections with carb cleaner to find your possible vacuum leak. If you have a leak, it will suck it up and cause the engine to stumble.
TPS and IACV aren't related. The IACV is controlled completely by the ECU and maintains proper idle speed based on ECT.