[Wiiums]

Since buying my new Outback 5 spd in November, I noticed that when cold and the clutch is disengaged, the car idles around 3000 rpm and gradually drops. The check engine light didn't come on, but after plugging in my new scan tool yesterday the P1507 was pending. I know the problem is with idle control, but if anyone could tell me the solution that'd be great.

Thanks

 

[cardoc]

It is a 2001 as you have in your info?

Its either a pretty good size vacuum leak or the IAC is no good. Did you check to make sure the throttle cable is not hung up on something holding the throttle open?

No other codes?

You could try removing and cleaning the carbon from the IACV and see if it helps. If there is not a leak in the intake or a disconnected vacuum hose, it will most likely be a bad IACV.

 

[jkenosh]

i would clean the idle air circuit if you have the hood open and are looking at the throttle body it is right by the throttle cables, held in with 2 phillips screws

 

[eagleeye]

Hi this video may help you. It shows how to address a vacuum hose leak and also the iac motor. ~shaun

how many p1507 threads does this forum have exactly ?

 

[CCCars]

Just done a search for P1507 and only got 4 hits so here goes car starts normally from cold, normal fast idle then after warm up period idle speed drops as normal but to about 1100 rpm instead of its usual 700ish, at this point the CEL comes on and code P1507, sometimes there is a high idle speed detected message but the engine rpm signal is correct at about 1100 rpm which agrees with the car tacho.
There is an occasional slight surge in rpm when idling which is sometimes regular then clears for a bit then starts again often when the cooling fan kicks in.
I'll try taking the IACS unit off tomorrow and give it a squirt of magic spray, I unplugged the IACS valve and nothing happened, idle speed stayed the same and engine would rev the same as with it connected so I'm guessing that's the problem?
Any other suggestions?
Thanks
Graham

 

[XPGeek]

@CCCars , check out my thread. I've basically tried all the common things so far, but am getting into the weeds (as the issue still exists). Should have more parts coming in soon.

 

[CCCars]

Cleaned the IAC valve and now it's OK, just a slight misfire at idle but not throwing up a fault code, could be a coil pack dying I had to change one a while back, hope it's one of the front ones!
Graham