1986-93 Ford Mustang 5.0 5.8 Idle Air Control (IAC) Adjuster - Fox Body by Ford

Mustang Idle Air Control (IAC) Adjuster (86-93) 5.0 5.8

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Mustang Idle Air Control (IAC) Adjuster (86-93) 5.0 5.8

Having trouble getting the idle of your 1986-93 Ford Mustang 5.0/5.8L where it needs to be? check out this Idle Air Control Adjuster!

Item #LRS-9939A

Everyday Low Price: $56.99

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  • Allows Easy Adjustment Of Idle
  • Smoother Operation For Modified Engines


  • Aluminum Construction
  • Easy Installation
  • Includes New Gaskets And Hardware
  • Fits 1986-93 Ford Mustang 5.0/5.8L

What's in the Box

  • (1) Adjustment Plate
  • (2) Gaskets
  • (2) Bolts
  • Installation Instructions

Product Description

This will put you one step closer to solving your idle problems! It is a must for modified 1986-93 Ford Mustangs! This thin, adjustable aluminum plate fits between the throttle body and the idle air control motor. It allows you to adjust the flow of air in and out of the idle air control motor for better control of your Mustang’s idle speed.
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Customer Reviews

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7 reviews
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7 of 7 REVIEWS
7 of 7 REVIEWS

  An excellent quick cure to a bad headache
By on 4/29/2014
Image uploaded by Mark  C. This kit is a simple and easy install that cures any fox that has been modified and has idle issues. It installs quick and easy,and does exactly what it says it does which allows the engine to idle without surging and/or dying. A must for any fox with aftetmarket camshaft!

Yes, I would recommend this item to a friend!

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  Awesome fix to a terrible headache!
By on 4/21/2014
I just recently installed an E cam in my 90 LX,and after numerous attempts to get it to idle somewhat normal,I ran across some posts on the web of people trying the idle air control adjuster kit,to help modified mustangs idle normally. And boy did it help and solve a huge problem for me! Love it,and HIGHLY advise it to anyone having idle surges and dying problems! Awesome little kit!

Yes, I would recommend this item to a friend!

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  Great product, but clean off the loctite.
By on 8/21/2014
I just installed this to help cure my cam-induced idle issues. My only word of warning with this is that the longer bolts supplied come with thread-locker pre applied. When I tried to remove the plate again I ended up twisting off one of the bolt heads and nearly did the same to the other. I had to use vice-grips to get the rest out, which was also nearly impossible. The threads in my Holley aluminum TB were slightly galled, but not to the point of needing repair. I don't see a reason that one would assume that this is a permanent install, so I would recommend cleaning off the thread locker first, and/or using "blue" thread locker if you must.

As for the functionality, I like that I can fine tune the idle without messing with the throttle plate. I did find that removing the plug in the third crossover port was necessary for my setup if the TB plate is to stay completely closed (normally only used in the 351), but luckily it comes out easy and can be reinstalled in a couple of minutes if needed.

Yes, I would recommend this item to a friend!

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  great fit and easy adjustment
By on 4/16/2014
Allowed me to adjust air flow with ease. My car is supercharged so finding something that allows me to do this easier is always a good thing. Quick install, affordable and made by well known 5.0 parts manufacturer.

Yes, I would recommend this item to a friend!

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  Easy Fix
By on 4/28/2014
Bought this to fix an idling issue I had with my 92 Lx 5.0 and it did the trick. Hard to find item and well worth the money if you have a cam or just want that perfect idle this may solve your idling issues.

Yes, I would recommend this item to a friend!

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  Finally I have an idle!!!
By on 4/22/2014
After a month of trying to get my 88 GT with aftermarket cam, throttle body, MAF, cold air intake I can finally idle this car with no problem. Even on a cold start!!! Recommended!!

Yes, I would recommend this item to a friend!

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  Solved my problem
By on 5/10/2014
After installing an e 303 cam I had a hard time making the car idle like it should after installing this product the car idles at a constant rpm with no issues. Couldn't be happier and a must if your gunna run the E cam

Yes, I would recommend this item to a friend!

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Vehicle Applications

Ford Mustang - 1986 (86) - 1987 (87) - 1988 (88) - 1989 (89) - 1990 (90) - 1991 (91) - 1992 (92) - 1993 (93)

About This Brand

Ford Motor Company Genuine Parts, Motorcraft® Parts and Ford and Motorcraft Remanufactured Parts are all excellent choices when it comes to performance, longevity and value for your Mustang or SVT Lightning. And they’re all backed by a Ford Motor Company limited parts warranty*, so you know their parts you use are going to perform like they should. Put the same parts on your Lighting & Mustang that came from the factory!

Look for Similar Items by Category

Ford Mustang Parts » Mustang Engine & Underhood » Mustang Emissions & Sensors » Mustang Idle Air Control Motors (IAC)
1979-1993 Mustang Parts » 1979-1993 Mustang Engine Parts » 1979-1993 Mustang Emission & Engine Sensors » 1979-1993 Mustang Idle Air Control Motors (IAC)

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