Quote:
Originally Posted by cyberpine
I lost a great video of me sticking my finger in there and it whistling like crazy. The hissing sound that I've been hearing is definitley coming from that spot. Also, as suggested I plugged a&b of the ECM and placed in start position and you can hear it trying to extend the IAC constantly.. it sounded like a stuck dc motor.
I have the valve out - from the tip to the base the cylinder is out maybe like 3/4 of an inch. But it's does not manually move. Any way to test it? fix it?
Question, does the head penetrate fully inside that chamber? Is that the open or closed position when it does? Right now(as you see it) now the head appears to be hidden inside the hole - how is that also open? It's unclear what's it's closing.
Would you recommend this replacement part. $16 with shipping included!
Thanks.
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JC
IAC is a dual coil bipolar stepper motor. You can look up about stepper motors
here
Dealers used to have special test fixture that allowed to test them. Under no circumstances try to operate IAC unbolted from TB. The stepper will eject pentacle - you can not re-insert. If it makes continuous noise when A&B are shorted ECM is commanding IAC to close IA passage. There should be NO air going through. Over time carbon, oil deposits may build up and prevent IAC from closing off this passage. Carb cleaner and good brushing job will remove stubborn deposits. The head should completely close IA passage - amount of protrusion depends on head design.
When you shut off ignition ECM commands IAC to fully open position - wide open IA passage. When A&B are shorted ECM forces IAC to full close. You can disconnect IAC connector - and measure the extension of the pentacle. Re-install, re-connect - and allow ECM to move IAC into full open and repeat measurement. It is a poor mans functional check for IAC motor without resorting to parts swapping.
$16 it is a cheap verification of IAC functionality (parts swapping). In my case I resort to a large collection of used units from my JY trips.
//RF
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