legacycentral bbs

Saw that one of the wires on the IACV was broke open and exposed copper showing. Took the top part of the valve off the magnet part I guess. Spliced a new connector put it all back together in the same spot and not it idles at like 2100 rpm.

I let it idle for like 5-10 mins to see if it would readjust but nothing just idles super high.. Anyone know what I should do? I have a spare computer should I try changing them? It's a turbo model incase that helps

Coolant temp sensor is a common failure point to cause that. Also, if you have the IAC vale off clean it with something. A brake or carb cleaner made from petroleum distillates is a good start.

Put the car in reverse to maybe try and drive it around to figure it out or the computer might relearn and the check engine light comes on, Code 24 IACV. Now when that happens is it just the little top part that shorts out or is the whole thing fubar?

try reversing the wires and see if that makes a difference

all the wires are good test light confirms it. Ill try replacing the top part of the unit. Just a shitty design by subaru. CEL comes on at a stop but goes away while driving, still idles really high though. Super frustrating everytime i fix something on this car another thing breaks.

Did you mark where it sat before you took it off? I had to turn mine a hair to adjust it cuz i forgot to mark it before i took it off.

i didnt have to mark it cause the spots where the screws have been like sunburned onto the metal so i know its basically in the correct spot. can i adjust that thing while the cars running?

2100 rpm is about where it is with the IAC valve wide open. If it's mounted in the same location as when you took it off, I would say it's your wiring at the connector. Or maybe the valve is dirty and stuck open?

the valve might be dirty but i did just clean it a week ago, not very well cause i was pressed for time.. sucks. Ill recheck the wiring, how would you recommend slicing those wires together.

Check the resistance of each side of the IAC coil. Here's the snippet from the FSM.

http://www.main.experiencetherave.com/s ... C_Diag.zip

If the wiring from the connector at the IAC to the ECU is good, then it's likely the coil.

Also, have you tried resetting the ECU?

http://i630.photobucket.com/albums/uu27 ... G_0529.jpg


The one on the right is the stock one, note part number. The one on the left is one from a 92 N/A. Both are identical other than part number.

I have changed the computer, reset it, and sprinkled holy water. Im gonna try and recrimp the wires using heat shrink type butt splicers, in conjunction with heat shrink stuff. If this doesnt work im gonna drive off a cliff in it.

ok recrimped everything really good, all tight and secure. Still idles anywhere from 1500-2800, and no matter how i adjust the IACV its always the same except for the very extremes of the adjustment ( higher idle with CEL code 24 ). So im stumped... can i just pour sea foam down the hole on the side of the valve body? Could the coolant temp sensor be bad and not show a code?

How did the car idle before you fixed the wire?

Did you trace back all the wiring from the ECU to the connector? What is the resistance on each coil of the IAC top?

car ran fine before. Took it into PIA this morning and they told me since its not throwing a code that its probably just a gummed up valve and that i should get some GM Upper engine and Fuel injector cleaner, and pour/spray it in there and let it clean the gunk out.

What im wondering; is it possible to take the IACV off with out taking the intake manifold off. keep in mind i have changed the turbo to a TD04 so might be to tight?

Do you have a screw on top of the throttle body that looks like this?

http://www.main.experiencetherave.com/subaru/images/TB/

Yes I do looks very similar to that. What do u suggest

Screw it all the way down or at least until the idle comes back down to normal.

I ran into a similar idle issue several years back. Had a high idle, and could not figure out why. I checked everything, and all was good. Turned out I cleaned the throttle body, which had a black layer of sealant around it to only allow a certain amount of air to bypass the throttle plate. When I cleaned it, more air bypassed the throttle plate and caused a high idle. I finally found the screw on the TB after removing the bracket for the engine cover....it covers that screw perfectly. The needle valve chokes off the amount of air bypassing the throttle. Some of the throttle bodies do not have the screw....so I'm not sure why it's there.

Chances are that you may have had that one connector wire bad for a while, and maybe the previous owner tweaked the idle with that screw. In theory you should be able to screw that needle valve screw on the TB all the way in so the IAC valve completely handles the idle. What I did was use the select monitor and adjust the screw so that the duty % on the IAC valve was within factory specs.

Ill give that a shot thanks for the help above all. However I did finally get ahold of a multimeter and checked all the wires and so far two of the three are ok. Now either the the wire which is white with little red spots goes somewhere else or I just can't find it on the harness by the washer bottle. Also checked ohms on the sensor and it's within specs like the book says

^unfortunately my throttle body doesnt have the idle screw your talking about. super bummer. The whole thing just has me stumped.... I might have a bad wire but theres no check engine light.... but the check engine light comes on if i turn of the AC/DEF and let it sit for a minute.. so idk its really frustrating and i would like to kick the designer of the IACV right in the dick.

Did you do anything to the tps while messing with the iacv? Also, did you double check the hose from the iacv to the intake pipe isn't clogged or something? Just some ideas i had trying to figure out why the iacv would go crazy for no apparent reason.

never messed with the Tps and those hoses are such a pain in the ass to get to under the intercooler ill have to tear into it to check that, doesnt over heat though so id say those are fine. Probably and electrical problem or something small and stupid.

I would suspect you still have a wiring issue.

The middle wire at the connector should have 12v to it when the ignition is "ON". The other two leads go back to the ECU to control the idle.

Like i said two i got to ring but i didnt check that one with the key on . But still if its a bad wire why isnt the CEL coming on?

The OBD1 ECU's are sometimes not great on detecting faults. The OBD2 ECU's have more logic in them to detect faults.

It's just a good idea to check all the wiring and make sure you're getting the voltage/resistance readings you expect.

ya ill have to bum the multi meter from my friend again. This is by far the most frustrating car problem ive ever had. I feel like taking a sledge hammer to the IACV to teach it a lesson lol