How do you adjust the idle on a Subaru Outback?

[stonej]

If it is in the owners manual I sure can't find it.

 

[mulder]

If it is in the owners manual I sure can't find it.

You don't. It's adjusted by the ECU (engine computer) and not
externally adjustable. If you're having a problem with the idle speed
not being correct or being unstable, there may be an issue with the
idle air controller which is an ECU-controlled valve that regulates
the idle speed. Over time the IAC can become sticky from internal
deposits, it may need to be cleaned or replaced.

 

[Edward Hayes]

The idle speed is set by the computer and there is no external
adjustment. If you think the idle is too low (the tachometer is not
linear at the very low range) then something else needs correcting
like cleaning the throttle body. ed

 

[stonej]

OK, thanks. I was able to manipulate the engine speed by
pushing around what I thought was the idle.

 

[mulder]

OK, thanks. I was able to manipulate the engine speed by
pushing around what I thought was the idle.

You should NOT attempt to manually adjust the idle speed by turning
the stop screw on the throttle arm. This is an adjustment that sets
the minimum throttle plate opening but is not intended to be used to
set the idle. Changing its setting will alter the IAC calibration, and
the ECU will then "learn" around the adjustment. If the stop screw is
adjusted too far the ECU may not be able to compensate.
So, short answer- don't mess with that.