Vader talked about performing the following service on the IAC in response to an engine idle problem. (I'd guess it is a result of a sluggish IAC stepper motor and/or IAC air passages that are dirty or restricted. You can remove the IAC, carefully remove the pintle, clean the motor and worm gear, place one drop of oil on the gear, then reassemble. Work the pintle back into the rack gears, then thoroughly clean the IAC air passages.) Is the IAC pintle removal straight forward? Does it pull out, screw out?
Are there any dos and don'ts when peforming this service.
Thanks

 

I can't get a full "how to do it" answer either.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

DSouth,

DON'T do what I did the first time! I removed the IAC, plugged it back in to watch operation, then turned on the ignition. The IAC stepped the pintle out to full extended position until the spring took over and launched the pintle across the garage. A while later, after moving a couple of other cars and several pieces of equipment, I found all the parts I neeeded to reassemble the unit.

You can gently rock the pintle back and forth and allow the spring to extend it until it comes apart in your hands. Clean everything with lint-free cloths and a mild solvent. Harsh solvents can affect the insulation of the stepper motor coils. It's generally the dirt and buildup on this worm shaft that causes sluggish IAC operation.

When the worm gear on the pintle shaft is clean and dry, apply one drop of clean light oil to the shaft and work the pintle back into the rack gears of the motor by the same rocking motion. It takes a while to get the pintle back into the worm gears, but you'll get it. It is important to get the pintle fully retracted into the housing so that the pintle is not forced against the gears when reinstalling the IAC unit in the throttle body.

While the IAC is out, clean the air passages in the throttle body. The oriface in the TB where the IAC resides is the seat that the IAC valve closes against, and it can accumulate a lot of carbon, dirt, and debris. The easy way to do this is with carburetor cleaner and a small stiff brush. Another "DON'T" - don't use your sister's toothbrush.

When everything is clean and dry, replace the gasket if it is damaged, apply a little anti-seize to the threads, and torque the IAC to the proper specs. (13 ft/lb for '85-'89 , 30 in/lb for 1990-on.)

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Later,
Vader
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"No matter how hard you try you can't stop us now"
Adobe Acrobat Reader 4.0

 

Hehe, so you did that too Vader? That bugger really springs outta there :-). I just wound up buying a new one because I didn't figure out that you could work the pintle back into the worm gear. Oh well live and learn.

 

Vader,
Thanks much. Very good description.

Now I have something to work on while waiting for that turkey dinner.

I'll also admit to launching parts from a hydraulic roller lifter when I used a small screwdriver to pry out the plunger retaining clip. I heard parts bouncing around the garage, but never did find that little retaining clip. Oh well, live and learn.

Later, DS

 

Man,

You screwed it up - she's probably already read this. And, there's some 90 wt. left over from the gear rebuild I just finished.

BOR

 

Vader, that was very informative. I'm about to work on a friend's IAC so File --> Print.

Get Dirk to put that up in the tech section, dammit!

 

Thanks for the info, Vader. I did my backup IAC last night.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9