IAC Repair

snowfish
Elite Member
Joined: February 23rd, 2009, 8:14 pm

May 22nd, 2012, 4:31 pm #1

I ran into another crappy IAC last night.

The IAC, Idle Air Control, or sometimes call the Solenoid Valve, is a controlled vacuum leak, to adjust the idle, to compensate for electrical loads.



1995's, and up, have an ISC. :news Idle Speed Control. This procedure Does Not apply to these models. :shake

A corrupt IAC can be one cause of high idle and or surging idle. :die If you can blow air through the hoses, with your mouth, not compressed air, the the IAC needs attention. :gamerz Here's how........

Gently bend the tabs back.



Chances are you'll find this



or this



The little brass arms are the Plunger return spring. All three are supposed to be connected to the seal ring. ^o) If separated, or partially separated, they are shot.

Grab a retractable pen,



Remove the spring and trim to size.



Install spring in the hole under the plunger cavity.



This height seems to work pretty good.



Trim the old, broken, brass spring legs to prevent interference and maintain balance of the plunger. Lay seal in the recesses of the IAC housing.



Reinstall the top and bend the tabs back.



Reinstall IAC, with New Hoses, and enjoy your new found stable idle. :cheers
............I'll be back in a bit........



IC3
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Memphis metro
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Joined: January 20th, 2010, 2:06 pm

May 22nd, 2012, 4:37 pm #2

Nice, thanks.
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Bad Bent
Elite Member
Joined: December 26th, 2008, 6:38 am

May 22nd, 2012, 6:55 pm #3

Excellent! Thanks for the bookmark. :thumb :thumb
Have fun...
BadBent
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"Goody Two Shoes" 1996 Metro, The Wife's car. 3Tech "econo" cam, +10 gear, Al. underdrive pulley, K&N, KYB, Bosch, Magnaflow, Syn. & grounded. No TB bridge.
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Rooy
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Joined: October 25th, 2008, 1:12 pm

May 22nd, 2012, 10:28 pm #4

Very nice. I need to open mine up.
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Turbo Dan-O
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Joined: May 10th, 2010, 1:46 am

May 22nd, 2012, 11:57 pm #5

Thanks for the great writeup Snowfish! I have been reading some of your other post on this lately because I have been fighting the famous "high idle" for a while now. I took my IAC off, inspected it(spring was fine) and cleaned it along with all of the other things to try but I still have the same problem. I just checked it again and yup, I can blow through both lines no problem. The lower line makes a sound like it is trying to close when I blow hard on it. Think I should try your spring idea???

Update: Just bypassed the IAC and she idles perfect. Thank you Snowfish that's what's wrong with it! :thumb :thumb :thumb
Last edited by Turbo Dan-O on May 23rd, 2012, 12:09 am, edited 1 time in total.
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calinip
New Member
Joined: June 22nd, 2012, 2:49 am

July 9th, 2012, 2:12 pm #6

so i had detected that my IAC does not work. I went ahead and took mine apart to check and low and behold. its shot!!!! I also noticed that when i took it apart, there was no spring present. wtf?! this IAC is well over $100. for now i found a way to make it work. i just plugged the top line and idle is normal

Thank you Snowfish for this helpful post!!!!!



Last edited by calinip on July 9th, 2012, 2:13 pm, edited 1 time in total.
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Coche Blanco
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Joined: July 16th, 2009, 2:22 am

July 9th, 2012, 2:14 pm #7

Yep, I bypassed my IAC valve months ago. I don't have A/C so that helps. If I did, I would bump my idle up manually during the summer months to compensate.
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snowfish
Elite Member
Joined: February 23rd, 2009, 8:14 pm

July 9th, 2012, 3:46 pm #8

calinip wrote:I also noticed that when i took it apart, there was no spring present.
Those little brass legs are the spring. It's amazing they last as long as they do.

Adjust the pen spring so it just makes a seal. Too tight and it will not function properly. It's quite a bit stronger that the light brass fingers.

Running with the IAC line plugs works. But headlights will drag the engine down. You may need to pump the idle, like Coche said, to compensate if it idles too rough.
............I'll be back in a bit........



IC3
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aryaan
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Joined: July 15th, 2012, 5:41 pm

July 15th, 2012, 5:49 pm #9

thanks its help me alots...
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iceman
New Member
Joined: October 5th, 2010, 9:45 pm

September 26th, 2012, 12:51 pm #10

I had some springs from a tumbler lock (for the pins) and that worked perf.
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