Idle issue

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logan9691
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Idle issue

Post by logan9691 »

Hi All,

I am having an issue with the idle on my '93 SS. You start the car up and it instantly jumps to 3,000rpm. If you unplug the IACV it will idle down a bit, but still remains high. The only code I am getting is 24, which is the IACV. I have swapped my throttle body with no change, and I changed the IACV motor with no change.

any thoughts? I'm pretty much stumped at this point.
VF43 custom FMIC APEXI intake Invidia 3" TBE JDM Ver. 4 RA STi trans (4.44) SPT short shifter rear LSD WRX rear axels coilover suspension JDM 4-pot front brakes drilled slotted rottors Greddy EBC tuned 20G ECU sti 550cc injectors Jecs MAF walbro 255
Legacy777
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Re: Idle issue

Post by Legacy777 »

Did this happen all of a sudden or did something change?

The fact that you have an IAC valve code would seem to indicate there is an issue in the electronics/electrical piece of the IAC valve. If you replaced the IAC valve solenoid and nothing changed I would suggest checking the wiring as there may be an issue, which is causing the problem.

Check out the diagrams in here and check the continuity of the wiring with a multimeter from the ECU to the IAC valve connector. It should be 0 ohms or close to 0 ohms.

https://www.main.experiencetherave.com/ ... C_Diag.zip
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
logan9691
Second Gear
Posts: 311
Joined: Sun Jun 15, 2008 4:40 am
Location: Ellensburg, Wa
Contact:

Re: Idle issue

Post by logan9691 »

I went from no high idle when starting the car cold and the car running rich (per wide band) all the time, letting off throttle car will not lean out. Then the engine harness got pulled on and now I have an idle that sits at 2,500 rpms, you touch the throttle and the car wants to “stumble”, the car is still running rich as well.
VF43 custom FMIC APEXI intake Invidia 3" TBE JDM Ver. 4 RA STi trans (4.44) SPT short shifter rear LSD WRX rear axels coilover suspension JDM 4-pot front brakes drilled slotted rottors Greddy EBC tuned 20G ECU sti 550cc injectors Jecs MAF walbro 255
logan9691
Second Gear
Posts: 311
Joined: Sun Jun 15, 2008 4:40 am
Location: Ellensburg, Wa
Contact:

Re: Idle issue

Post by logan9691 »

I’ve checked resistance in the engine harness and everything seems ok. I was leaning towards an ECU issue at this point. Tips for checking resistance in harness back to ECU?
VF43 custom FMIC APEXI intake Invidia 3" TBE JDM Ver. 4 RA STi trans (4.44) SPT short shifter rear LSD WRX rear axels coilover suspension JDM 4-pot front brakes drilled slotted rottors Greddy EBC tuned 20G ECU sti 550cc injectors Jecs MAF walbro 255
Legacy777
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Re: Idle issue

Post by Legacy777 »

You need to use the wiring diagrams and check the resistance of each sensor/pin going to the engine back to the ECU pin. You can d/l the manuals/diagrams from me.

viewtopic.php?f=12&t=14485
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
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