Cleaning IAC
Thread Starter
Melting Slicks
Joined: Jan 2005
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From: Phoenix, Arizona
Cleaning IAC
I have a '96 LT4 w/ BBK 52mm TB. Having some idle issues w/ the A/C on and was told to clean the IAC as that should correct the problem. Cleaned my TB recently but left it on the car and was told this time to remove it to clean and do the IAC as well - which requires removing the TB to clean.
Any tips on this?
Thx,
Jeff
Any tips on this?
Thx,
Jeff
Team Owner
Joined: Oct 2000
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From: Fort Knox, KY
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I just used an old toothbrush and a can of Valvoline Synthetic TB Cleaner to clean my IAC spring and pintle.
Be sure and replace the IAC gasket.
You can make one from gasket paper if you can't locate one at your parts counter.
Be sure and replace the IAC gasket.
You can make one from gasket paper if you can't locate one at your parts counter.
Last edited by onedef92; Oct 12, 2006 at 02:02 PM.
Drifting
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From: Chicago Executive Airport, formerly known as Palwaukee
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I would get a new throttle body gasket. The IAC motor should have a rubber o-ring. Just be careful taking the o-ring off of the motor. Don't get the cleaner on the o-ring. Clean it up real good and let it air dry. Reassemble and you should be good to go.
Melting Slicks
Joined: Nov 2002
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From: 1993 Quasar Blue 'vert Scottsdale AZ
Originally Posted by JEFNLSA
I have a '96 LT4 w/ BBK 52mm TB. Having some idle issues w/ the A/C on and was told to clean the IAC as that should correct the problem. Cleaned my TB recently but left it on the car and was told this time to remove it to clean and do the IAC as well - which requires removing the TB to clean.
Any tips on this?
Thx,
Jeff
Any tips on this?
Thx,
Jeff
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by onedef92
I just used an old toothbrush and a can of Valvoline Synthetic TB Cleaner to clean my IAC spring and pintle.
Be sure and replace the IAC gasket.
You can make one from gasket paper if you can't locate one at your parts counter.
Be sure and replace the IAC gasket.
You can make one from gasket paper if you can't locate one at your parts counter.
on the cleaning and I was unable to locate just the IAC gasket. Make sure when you install the IAC back into housing...that the tip of the pintle is no further than 1 1/8" from the flange. If it is any further it may damage the motor windings.
Burning Brakes
Joined: Dec 2005
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From: Hickory Flat Ga
My AC compressor was going bad and caused bad idle and a code for the IAC. Really bogged it down. Is it spinning freely? New compressor cured my idle with AC on. Just a suggestion.
Corvette=Adventure
Corvette=Adventure
Le Mans Master
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From: Alive and well in Burlington NC
Originally Posted by RRT vette
on the cleaning and I was unable to locate just the IAC gasket.Corvette Stories
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Team Owner
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From: Fort Knox, KY
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Also, don't forget to clamp the TB engine coolant hose (LT-1, LT-4) before you remove it or you'll risk dousing your Opti with just enough coolant to possibly tank it.
Thread Starter
Melting Slicks
Joined: Jan 2005
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From: Phoenix, Arizona
Originally Posted by Lichen
Hey Jeff, thanks for the question. I'm having the same problem. When I turn on the AC, the idle goes to crap. Let's get together sometime.
I actually fixed this a while back. Took the car to Bill's (ZFDoc) & pulled the TB. Cleaned it thoroughly as well as the IAC and *bingo*, problem solved.
Mike @ ADS told me he was quite sure that the IAC was the culprit..."needed cleaning". You have to remove the TB to get to it so I went ahead & did a serious cleaning job on both. Idle immediately returned to normal.
Give me a call or PM me if you want to get together.
Cya,
Jeff
Le Mans Master
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Originally Posted by RRT vette
on the cleaning and I was unable to locate just the IAC gasket. Make sure when you install the IAC back into housing...that the tip of the pintle is no further than 1 1/8" from the flange. If it is any further it may damage the motor windings.
Team Owner
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From: Fort Knox, KY
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Don't forget to put a dab of motor oil around the TB gasket before you screw it back to the TB housing. This ensures an air-tight seal and prevents possible vacuum leak.
Le Mans Master
Joined: Jul 2002
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From: Alive and well in Burlington NC
Originally Posted by onedef92
Don't forget to put a dab of motor oil around the TB gasket before you screw it back to the TB housing. This ensures an air-tight seal and prevents possible vacuum leak.
I use a high vac silicone grease on all TB gaskets just to be sure. It also makes it easier to disassemble next time. 
Le Mans Master
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From: San Diego, Ca
Scan it first and verify that there's an a/c signal along with an increase in IAC counts. A/c signal is from the Programmer with the circuit completed through the Low Pressure Switch. The IAC counts are actually bumped up a nano second before the ECM grounds the Compressor Relay, but it's difficult to capture that on a scan. In any event, with the compressor turning, your scan should show "Yes" and the IAC counts should increase to something in the 20's. When the low pressure contacts open, the compressor should shut off and the counts should drop. If that much is there, suspect the IAC. If it isn't you'll need to troubleshoot the a/c signal, ECM.
