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Old 10-01-2012, 08:53 PM   #1
wrxguy04
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Default IACV Problem

Car: 2004 WRX
Mods: full exhaust, headers, tune

*freshly rebuilt as today was the first day i drove it after a year and i went 50 miles!
So today i was driving the car and it seemed like a TPS problem so i switched it out with a new ine. THAT problem went away and then it started idling up and down in park and neutral and kind of high around 1500RPMs.

I scanned te code and got a P0507 for IACV RPMS being higher than expected and also a P0519 for IACV syatem malfuntion.

Here's the thing.. I've cleaned it twice with gasoline, let it evaporate, then used alcohol and q-tips to clean it and made sure te valve moved freely.

The question: where or how should i go about fixing this problem? Buy a new one?
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Old 10-01-2012, 09:00 PM   #2
Dr. octagon
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find a homie and swap in his iacv for a go. As i remember those things ant cheap. Go back over your install and make sure the gasket is seated and new.

Is the flapper in the iacv moving (can you move it/open and close it)?
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Old 10-01-2012, 09:04 PM   #3
wrxguy04
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Yeah i tried to get my buddy to bring his 03 over to try his out but hes busy but yeah the gasket is good and seated and the valve is moving freely
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Old 10-01-2012, 11:36 PM   #4
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Old 10-02-2012, 12:55 AM   #5
wrxguy04
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No but i will tomorrow for sure! I tried using the torx bit but dam thise are a pain to get out and end up stripping
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Old 10-02-2012, 09:58 AM   #6
rocketperson7
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if it does not spin like a top, it is not clean, carb cleaner/some other solvent is your friend

I think that's one of the #1 mistakes
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Old 10-02-2012, 04:47 PM   #7
wrxguy04
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I think the bearing in mine is too dry because i spun it and it doesnt spin like a top to be honest
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Old 10-03-2012, 12:25 PM   #8
wrxguy04
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Good god this throttle response is killing me!
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Old 10-03-2012, 06:36 PM   #9
wrxguy04
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And now i have a cylinder 4 misfire. Great
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Old 10-03-2012, 07:12 PM   #10
2gnt2wrx
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Well throttle response and cyl4 misfires shouldn't have much to do with your iacv.

I don't like the idea of submerging the iacv in solvents because the bearings have grease in them which is most likely... well... desolved...

I would run the car and take the oil fill cap off and see if there is smoke. Then run a compression test.
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Old 10-03-2012, 07:54 PM   #11
wrxguy04
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I checked compression and they were all at around 130-140 last week but thats before i drove it about 100 miles around town but its freshly built aka new rings, honed cylinders and new head gaskets.

Ill post compression test results shortly and see what to do from there. Other than that, i pulled the plug from cylinder 4 and it was a burnt tan-ish color and there is no smoke from the oil filler cap an i checked the oil before and after each drive and its still golden brown
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Old 10-04-2012, 12:57 AM   #12
wrxguy04
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Cylinder 1- 135 psi

Cylinder 2- 120 psi

Cylinder 3- 125 psi

Cylinder 4- 120 psi
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Old 10-04-2012, 08:37 AM   #13
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Quote:
Originally Posted by wrxguy04 View Post
Cylinder 1- 135 psi

Cylinder 2- 120 psi

Cylinder 3- 125 psi

Cylinder 4- 120 psi
cold?
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Old 10-04-2012, 10:40 AM   #14
wrxguy04
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Quote:
Originally Posted by 2gnt2wrx

cold?
Yes sir
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Old 10-04-2012, 02:25 PM   #15
2gnt2wrx
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To get an accurate number you will have to let it run until it's at operating temp then re-do the test.
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Old 10-04-2012, 03:16 PM   #16
wrxguy04
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Okay will do, i didnt know that. Thanks!
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Old 10-04-2012, 03:22 PM   #17
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Buy a new AICV, if cleaning didn't fix it, only replacing it at this point will. Also try swapping your coilpacks around and see if the misfire follows the coilpack. That is a sign it's a bad coilpack.
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Old 10-04-2012, 03:40 PM   #18
wrxguy04
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Yeah im going to get an iacv from a friend for cheap that works well, clean it, take the old one off an replace the gasket and it should be good.

As for the misifre, it was a fouled plug so it has been replaced. The coil packs are new
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Old 10-04-2012, 03:43 PM   #19
wrxguy04
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Also, just ran a warm compression test and they are all at 125 psi
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Old 10-05-2012, 02:56 PM   #20
wrxguy04
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Extremely jerky acceleration and in first, takes a secon to build up but runs up high into boost and charges like hell then in second does the same but full power shifting out of first, third is good as well but fourth is horrible and little to no power.

Low power take off without going into first and shifting through the gears (4eat transmission by the way) and boost fluctuates. Not sure whats going on. Only code is IACV revolutions higher than expected. Help!
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Old 10-05-2012, 06:52 PM   #21
wrxguy04
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Bump for helppp
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Old 10-06-2012, 12:58 AM   #22
2gnt2wrx
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I suspect you have a major boost leak. Check every connection between the air filter and turbo, then check every connection from the turbo to the intake manifold. If your boost is all over the road I am willing to bet you have a post turbo leak.

You could make a boost leak detector or possible find someone local that has one.

Last edited by 2gnt2wrx; 10-06-2012 at 09:57 AM.
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Old 10-06-2012, 12:05 PM   #23
wrxguy04
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Yeah i suspected a leak or many as well so i have a leak tester that i made out of a PVC pipe end cap, high pressure hose and a shut off valve with gauge, ran 20psi through the air system and did the soapy water spray. This was two days ago

Turns out i had 4
-bypass valve to intercooler leak: fixed
-turbo inlet to turbo: fixed
-boost gauge T: fixed
-intake manifold to TGV on cylinder 2: fixed

Maybe i should try cleaning MAF, BCS and what not? Anymore suggestions on what to clean besides IACV since i have already done so a few times with no good turnout?
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Old 10-06-2012, 02:46 PM   #24
2gnt2wrx
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Just make sure to spray up into the maf its pretty hard to see the little wire up there.
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Old 10-06-2012, 04:21 PM   #25
wrxguy04
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Well see i have a good MAF but its dirty and then the new one i from ebay and its a different voltage or something so its throwing a code so i need to clean my old, good one and try it
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