Subaru Outback Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

1 - 19 of 19 Posts

·
Registered
2005 Outback 2.5 SE (UK spec)
Joined
·
31 Posts
Discussion Starter · #1 ·
Hi all, my 2005 outback 2.5 SE (72,000 miles) appears to idle a little lower than normal at 500rpm and when driving out and about stopping at junctions the revs tend to bounce when settling down to idle OR even the car stalls at junctions sometimes. There are no warning likes coming up or error codes.

The car is recently serviced with new plugs and filters to see if that would help, but made no difference. Are there any sensors or throttle body adjustments to check or play with? Does the ecu need to be checked by a dealer?

Any advice or tips to help would be nice before I head to a dealer and spend silly money.

Cheers

James
 

·
Registered
Joined
·
288 Posts
See:
Idle Air Control Valve Cleaning... Problem.. - Ultimate Subaru Message Board
for cleaning.
Get a new gasket before you take it apart and the old one is unreuseable. The screws are in tight. PB them first. I just use an impact sxrewdriver. You'll have to remove a few hoses to get to it. Make sure the large hose is reattached to the snorkle, or it'll die on you while trying to start it.

For future ref:
http://opposedforces.com/parts/legacy/
www.main.experiencetherave.com - /subaru_manual_scans/

O.
 

·
Registered
2005 Outback 2.5 SE (UK spec)
Joined
·
31 Posts
Discussion Starter · #5 ·
See:
Idle Air Control Valve Cleaning... Problem.. - Ultimate Subaru Message Board
for cleaning.
Get a new gasket before you take it apart and the old one is unreuseable. The screws are in tight. PB them first. I just use an impact sxrewdriver. You'll have to remove a few hoses to get to it. Make sure the large hose is reattached to the snorkle, or it'll die on you while trying to start it.

For future ref:
http://opposedforces.com/parts/legacy/
www.main.experiencetherave.com - /subaru_manual_scans/

O.

Excellent many thanks and ill try this out once I get the part:29:
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,505 Posts
Your car has electronic throttle. Drive by wire. The motor that operates the throttle plate also works the plate for idle air control.

Its still most likely carbon buildup throwing off the throttle position data sent to the ECM, just its the carbon on the throttle body.

It can be cleaned with a soft bristle tooth brush and the proper cleaner. You can pick up throttle body cleaner at the parts store. Don't use carb cleaner. Get the cleaner that's safe for electronic throttle bodies. CRC is a good brand.

Disconnect the battery prior to cleaning and make sure its dry before reconnecting the battery and starting the car.
 

·
Registered
2005 Outback 2.5 SE (UK spec)
Joined
·
31 Posts
Discussion Starter · #7 ·
Your car has electronic throttle. Drive by wire. The motor that operates the throttle plate also works the plate for idle air control.

Its still most likely carbon buildup throwing off the throttle position data sent to the ECM, just its the carbon on the throttle body.

It can be cleaned with a soft bristle tooth brush and the proper cleaner. You can pick up throttle body cleaner at the parts store. Don't use carb cleaner. Get the cleaner that's safe for electronic throttle bodies. CRC is a good brand.

Disconnect the battery prior to cleaning and make sure its dry before reconnecting the battery and starting the car.
Can I clean without having to remove the throttle body and AICV? Or better to just do it right from the outset when I do it.
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,505 Posts
You can clean it on the car. The throttle plate can be moved by hand to get the area in front and rear of where the plate rest closed. If you want to remove it, its one plug, 2 clamps on the coolant bypass hose and 4 fasteners. The gasket should be reusable. Removal would make for a more efficient cleaning and make it easier to get the interior side of the throttle plate.

Either way, make sure it is dry before you turn on the key and put power to it.

There is not an IACV on your car. Its all managed by the motor assembly attached to the throttle body on the passenger side.
 

·
Registered
2005 Outback 2.5 SE (UK spec)
Joined
·
31 Posts
Discussion Starter · #9 ·
Cardoc- Do you know the part number or picture of the gasket? I think I should order one just in case as I'm going to take it off completely to do the job right.

Out if interest... If this does not solve it... What should I look at next?
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,505 Posts
You will only find the gasket at Subaru.

If this doesn't solve the issue, then you'll have to look into the type of fuel used, fuel delivery or clogging exhaust.
 

·
Registered
2005 Outback 2.5 SE (UK spec)
Joined
·
31 Posts
Discussion Starter · #11 ·
Hi cardoc, spent yesterday removing and cleaning the throttle body now I'm back fom being away on business. Needed a good clean! Checked the movement of the butterfly / choke and ensured all the gears from the motor are fine.

Put it all back on and went for a drive... Sadly no difference to report.

I noticed some toggle Alan key screws withing the electronic gears / motor housing the control the spring position and set about turning return stop one. Moved it 2 whole turns and put it all back together... Went for a drive and found the resting revs were higher at 900rpm but the revs bounced lots before settling. So I went back and toggled it the opposite it way and the car stalled very easily. In the end I put the toggle screw back to where it was and back to where I started

Totally enjoyed tinkering but no further forward.

I noticed there is a pressure map sensor, anyway to test if this is faulty? Or could this be the cause.
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,505 Posts
Without a scan tool that reads live data, you'd have difficulty testing all the circuits. With a scan tool that will read the data, you compare throttle position with the pedal position in relation to the target idle. You would also look at HG measurement, AF sensor data and rear O2 sensor output.

High alcohol content fuel will cause a low idle in cars that are not programmed to adjust for it.
 

·
Registered
2005 Outback 2.5 SE (UK spec)
Joined
·
31 Posts
Discussion Starter · #16 ·
Without a scan tool that reads live data, you'd have difficulty testing all the circuits. With a scan tool that will read the data, you compare throttle position with the pedal position in relation to the target idle. You would also look at HG measurement, AF sensor data and rear O2 sensor output.

High alcohol content fuel will cause a low idle in cars that are not programmed to adjust for it.
Seems that will be my next step via the dealer I think... I read on other forums that the idle can be raised but has to be done via the computer / diagnostics being hooked up. So me adjusting those screws on the throttle body will not help as the cars management will just try to compensate I guess based on parameters that have been set.

Once I know more or find a solution ill update this thread.
 

·
Registered
Joined
·
1 Posts
Seems that will be my next step via the dealer I think... I read on other forums that the idle can be raised but has to be done via the computer / diagnostics being hooked up. So me adjusting those screws on the throttle body will not help as the cars management will just try to compensate I guess based on parameters that have been set.

Once I know more or find a solution ill update this thread.
Did you ever figure out the final solution for this issue? I think I am having a similar issues on my 2010 Subaru Outback. Thanks.
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,505 Posts
@FSUguy If your engine idle is low, first check is for codes on the car. Is the engine light or other lights on? No codes, clean the throttle body with the battery disconnected and when you're done cleaning, hook the battery up, turn the key on, don't start, let it sit on for a few seconds, the gauges will sweep, then off, then start and let it idle for about 5 minutes. Drive it around the block and see what it does.
 
1 - 19 of 19 Posts
Top