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Guest Message by DevFuse

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IAC Replacement

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10 replies to this topic

#1 MailManX


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Posted 09 February 2004 - 01:47 PM

Looks like I need a new IAC valve. What is a good source online to buy one of these cheaper than at the local stealer?

And just for the record, here are the symptoms. Tell me what you think (this is on a 1993 Legacy L AWD with Manual Trans):

A couple of weeks ago my car started idling funny. Sometimes it would idle way too fast. Other times the idle would fluctuate a lot. From there, it progressed to stalling out at stop lights. Finally, it would even try to stall under mild acceleration. However, it would usually catch again just as it died and I'd hear a terrible amount of CLICKING under the hood.

After a search on this board, I carefully removed and cleaned the IAC. It was very sticky and a lot of crap came out of it when I cleaned it with a good quality brake parts cleaner. But, alas, it didn't cure the problem. In fact, when I put it back together I tried to reset the ECU. Unfortunately, the car wouldn't even idle after I reconnected the negative battery cable. It would just click a lot, then die.

Thus, I conclude my IAC valve is shot. Sound logical?


P.S. - Be sure to let me know a good source to order one of these.

#2 frag


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Posted 09 February 2004 - 02:11 PM

246.17$ at https://www.1stsubar...m/partscat.html

#3 DerFahrer


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Posted 09 February 2004 - 03:46 PM

Hey Michael, you've got two options for IAC valve replacement:

1) The stealership (mine list was over $360!!! :eek: )
2) A junkyard
3) A parts warehouse like www.4subarusuzukikiaparts.com

I don't know of anyone that rebuilds them and Autozone or Advance won't have them.

Replacing one isn't exactly a picnic either, but I do remember how to do it and can offer plenty of advice on it...

Good luck!

#4 MailManX


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Posted 09 February 2004 - 04:27 PM

Thanks Frag and Subyluvr for the links to online purchase. I checked with my dealer and they wanted $338.

I've already had the old IAC off once to clean it, so replacing it won't be as hard. All the hoses are already broken loose and will come off easier this time.

Here's a question: Before I did anything to the car, I hooked up the black connectors under the dash and read the codes. But there weren't any codes to read. I guess the ECU doesn't realize that the IAC is bad. And just to make sure I was doing it right, I read the codes again after disconnecting a couple things to get to the IAC and I got multiple codes.

Is it normal for the ECU not to recognize a bad IAC valve?


#5 Guest_jclay_*

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Posted 09 February 2004 - 05:47 PM

I had the same IAC situation just a few weeks ago, sudenly the car was idling at almost double what is normal. I pulled the codes, it came up "24" (i don't have my chiltons handy to tell you exactly what that is, but it was something along the lines of the IAC)

anyway, i took the car to my TRUSTED mechanic, who said he usually had good luck cleaning the valves as you've done. he pulled the valve, found that it was clean(ish) and replaced it. The car was still idling funny. He suggested that only the sensor on top was bad, and could be replaced independantly. He also showed me how to adjust the idle with the IAC. Simply loosen the 2 screws that hold the top sensor part to the body, then pivot the sensor to adjust the throtte, retighten the screws in the desired position. If your car isn't idling at all, perhaps it just has to be adjusted higher.

anyway, thats what i did, and i was able to score the sensor part alone from a junkyard, although thats always a crapshoot(IMHO) i haven't tried it yet, simply b/c its been too frigid here in Maryland to go tinkering after dark (no garage) i may try this weekend if it warms up, and i'll let you know how it fares.

anyway, thats my 2 cents worth, hope it helps in some way.


#6 MailManX


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Posted 09 February 2004 - 06:03 PM

I hadn't thought of adjusting the idle by repositioning the electromagnet on the top. I'll give that a shot! Worst case, I still have to buy a new unit, but I haven't lost anything by trying.

#7 lmdew



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Posted 09 February 2004 - 06:24 PM

I have several used if you want to try one. $15+10 shipping. Lmdew@hotmail.com

#8 Legacy777



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Posted 10 February 2004 - 08:48 AM

the valve is calibrated, so if you do move the electro magnet portion....make sure you scribe where it sat.....it's one of those things I personally wouldn't mess with......reason.....you're fixing a symptom, not necessarily a problem....

#9 MailManX


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Posted 10 February 2004 - 08:58 AM

Thanks to jclay for the advice on adjusting the electromagnet on top of the IAC valve because it caused me to find the REAL problem. It was simply a bad spark plug wire that was arcing to a nearby bolt up on top of the intake. DUH!! I guess that explains why I could not find any ECU trouble code. It sure doesn't pay to over think a problem.

A new set of sparks plug wires and the car runs great again. I'm sure glad I didn't already order the new IAC valve. I'm also glad that my cleaning of a perfectly good valve didn't ruin it!

I almost didn't post this since it's pretty embarrassing. But if someone else can benefit from my lesson, that's a good thing.


#10 sub87dl


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Posted 10 February 2004 - 09:01 AM

Originally posted by MailManX
However, it would usually catch again just as it died and I'd hear a terrible amount of CLICKING under the hood.


Now we know what that CLICKING sound was!


#11 Cougar


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Posted 11 February 2004 - 04:55 AM

It's the simple things in life that make it so nice. Glad you got the problem solved without much trouble and expense.

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