High idle in between shifts.

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martimus919
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High idle in between shifts.

Post by martimus919 »

So I am thinking that the source of my problem is the IAC but wanted to make sure before I went and bought a new one.

But it does it more when it's hot or after I boost a little hard, I don't need to go full throttle. But the RPM's take a while to go down, way too long for me to wait to shift.

Another thing that makes me think it's the IAC is that my brakes get squishy every so often and I thought it was a bad master cylinder after I did a bench bleed then bleed the whole system. I then replaced it and same symptoms came up making me believe a bad vacuum.
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
Legacy777
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Re: High idle in between shifts.

Post by Legacy777 »

I would be surprised if your problem is the actual IAC valve and not something else. The high idle is a symptom, and the IAC valve is likely not the cause, but another issue.

Have you checked for any stored codes and done an active diagnostic with the green diagnostic connectors?

Can you run Vikash's scan tool to see what the IAC valve duty %'s are doing? Have you checked for vacuum leaks?

I would suggest doing a few other checks/tests before going directly to the IAC valve.
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
martimus919
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Posts: 222
Joined: Sat Sep 19, 2009 6:21 am
Location: Reno, NV

Re: High idle in between shifts.

Post by martimus919 »

I run Revscan Software from Revtronix. I have not checked the duty cycle of the IAC yet, but occasionally I get codes 24, 32, and 45. But only after harsh hesitation after turning right, which I'm sure is caused by fuel starvation.

I don't believe I have the best compression which may be a cause, last time I checked it it was pretty low. Also at idle it when cold it misfires, but seems to fade a bit when it warms up.

But I'll see if my Revscan can give me some readings on the IAC.
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
Legacy777
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Re: High idle in between shifts.

Post by Legacy777 »

Yeah check what you're seeing in revscan.

I'm not sure why you'd get those set of codes.....they're not exactly related. As I mentioned, I'd suggest doing an active diagnostic with the green connectors.
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
martimus919
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Posts: 222
Joined: Sat Sep 19, 2009 6:21 am
Location: Reno, NV

Re: High idle in between shifts.

Post by martimus919 »

Revscan showed that IAC Duty Cycle was at 25.4% at idle and I got it up to 54% while driving. I didn't get on it hard cause I was wearing my broken foot boot.

I also checked for any stored codes and there weren't any.

Now the active diagnostic test with the green connectors. I know how to reset and read codes with that but I am unaware of anything more than that. I stopped using them when I got the Revscan software working, mainly because it was easier to read codes with that than to do the whole procedure with the connectors.
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
Legacy777
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Re: High idle in between shifts.

Post by Legacy777 »

Based on your readings at idle (and I'm assuming the idle speed is roughly normal 750-800 rpm) your IAC duty % is too low, which to me indicates you have a vacuum leak some where or air bypassing the throttle body


Check out this thread for more info on where the select monitor values should fall in between.

http://bbs.legacycentral.org/viewtopic.php?f=19&t=24376

Double check for any and all vacuum leaks.

Also, do you have a throttle plate bypass screw on the top of the throttle body?

http://main.experiencetherave.com/subaru/images/tb/
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
martimus919
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Posts: 222
Joined: Sat Sep 19, 2009 6:21 am
Location: Reno, NV

Re: High idle in between shifts.

Post by martimus919 »

I haven't had time to compare the outputs yet, but I looked into the bypass screw and I do not have one in my throttle body, but I just installed one this afternoon.

I looked at my spare block (original engine) and noticed it had one, so I swapped the 2 throttle bodies and put on a new gasket for safe measure.
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
Legacy777
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Re: High idle in between shifts.

Post by Legacy777 »

You don't need the bypass screw/TB with the bypass screw. It was not meant to be adjusted and was just a way they calibrated the TB from the factory. So I would not recommend just adjusting that screw as it may mask the problem.
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
martimus919
First Gear
Posts: 222
Joined: Sat Sep 19, 2009 6:21 am
Location: Reno, NV

Re: High idle in between shifts.

Post by martimus919 »

I was kind of thinking swapping the throttle bodies was going to be pointless, but at least it's got a new gasket on there. This weekend I'm going to see if I can find a vacuum leak somewhere, I'll let you know what I find.
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
martimus919
First Gear
Posts: 222
Joined: Sat Sep 19, 2009 6:21 am
Location: Reno, NV

Re: High idle in between shifts.

Post by martimus919 »

Okay no leak found yet, I spent a chunk of time looking for any leaks over the weekend and couldn't find anything so far. I am needing to build an insert for my intake so I can do a pressure test on the system so I can find the leak much easier.

But tonight after driving home (still erratic idle) I got home and the car would not idle lower than 2g for some time then lowered to about 12 and was not smooth at all. Check engine light came on, plugged in Revscan and pulled the code 24. Usually when I get this I can clear it or I can turn the car off and turn it back on and it acts more normal. Not this time, I cleared the code and it popped back on just a second later and kill the car and start again didn't work either. So I parked it and haven't driven it since. I'll find out how it does in the morning.
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
Legacy777
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Joined: Tue Oct 15, 2002 11:37 am
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Re: High idle in between shifts.

Post by Legacy777 »

I seem to recall another board member ran new wiring for the IAC valve from the ECU to the IAC valve and that improved/fixed his idle issues. If you know the IAC valve is good/ok and the ECU is good, that leaves the wiring.
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
martimus919
First Gear
Posts: 222
Joined: Sat Sep 19, 2009 6:21 am
Location: Reno, NV

Re: High idle in between shifts.

Post by martimus919 »

I've been afraid that the wiring is bad, I ran all new wires to the Canister purge solenoid valve after running tests for a code 35 and found everything to be fine but the wires. I'm also afraid that is was because of the intercooler laying on that part of the loom. I think I moved it too late before damage to the loom was done.

I'll test the system this weekend and let you know. I wish I didn't start hacking up my spare harness for my Brat, I would've just swapped the whole harness over.
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
martimus919
First Gear
Posts: 222
Joined: Sat Sep 19, 2009 6:21 am
Location: Reno, NV

Re: High idle in between shifts.

Post by martimus919 »

So I tested the AIC system and found wiring to be good. The one's that weren't right on were the following.

CHECK BYPASS AIR VALVE

Terminal: Resistance:
1-2 9 Ohms Results: 10ohms
2-3 9 Ohms Results: 10ohms

CHECK ECU VOLTAGE

Connector & terminal: Voltage:
(F47)2-Ground 7V Results: 12v
(F47)1-Ground 6V Results: .5v

ECU voltage is the only thing that I can think would be an issue. I got this ECU out of an auto a couple years ago, but as far as I understand they're the same, am I wrong on that?

Also found the culprit to the squishy brakes... Wheel bearing!! It was really bad, yet quiet for how bad it was.
07 Outback XT VF52
94 Legacy Sport, VF23, 550 RobTune, various other things
93 Legacy Touring Wagon EJ205 management and dash swap (in progress)
90 Loyale Turbo, EJ Turbo Swap, 2" lift
82 Brat, EJ22 swap, RX AWD trans w/ LSD rear, 5 lug 4 wheel disc.
Legacy777
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Re: High idle in between shifts.

Post by Legacy777 »

10 ohms is pretty close to the spec. It may be an indication the coils in the valve are wearing, but that's just a guess.

Your voltages are good. This is the spec for the turbo cars.

Connector & terminal: Voltage:
(F47)2-Ground 0V to 12V*
(F47)1-Ground 12V to 0V*

* 1 min after ignition is switched to ON

Here's the FSM info where I pulled that info.
http://www.main.experiencetherave.com/s ... 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
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