confused?!?!?

Landshark · #1 05-14-2003, 01:50 PM

i called the dealer to get a labor quote on getting the idle air control valve replaced. he said the main one is $175, the auxilliary one is $195. huh? "there's two?" "THAT'S WHAT THE BOOK SAYS"

what's the deal with the IAC valve(s)?

Landshark · #2 05-14-2003, 05:57 PM

^bump^

NOBODY has ever had the IAC valve replaced???

Beav · #3 05-14-2003, 06:50 PM

There's probably no reason to replace the IAC. Normally they only need cleaning (unless you drive a Ford.)

Landshark · #4 05-14-2003, 07:08 PM

Quote:

Originally posted by Beav
There's probably no reason to replace the IAC. Normally they only need cleaning (unless you drive a Ford.)

thanks Beav. are there two of them, though? (main and auxiliary)

Beav · #5 05-14-2003, 08:20 PM

There's only one that I can think of:

http://www.subaruparts.com/diag/?mod...ategory=063-A2

See: #2

Unless someone is confusing the IRIS valve for something it isn't.

cdigerlando · #6 06-03-2006, 06:36 PM

Here is the other one. http://www.subaruparts.com/diag/?mod...category=036-A

I have no idea what this does, as it is powered by 12 volts at all times and has no control signals whatsoever other than it shuts down when the fuel pump relay shuts down. I pulled mine off to check its operation using battery power. Seems to do nothing. I'm thinking about leaving it off the engine to see if it does anything, just bypassing it with a hose, as it always seems to be open. Maybe when it is hot it closes more? I'm confused too.

JDW-SVX · #7 06-03-2006, 07:05 PM

There are in fact two air control valves, the IAC (which controls the idle speed), and the Auxiliary Air Control Valve, which is used only to allow extra air to bypass the throttle plates when the engine is started from cold.

That valve is indeed controlled by the fuel pump relay, so that whenever the engine is running, 12V is supplied to the valve. Inside the valve is a bimetallic strip, which allows the valve to open when cold, and gradually close when 12V is applied, and the valve warms up.

If the valve is cold, it should only take a few minutes after 12V is applied for the valve to close completely.

Jason.

cdigerlando · #8 06-03-2006, 07:35 PM

Now that makes sense to me. Thank you for the clairification. I guess the only way to test the operation is to not only apply the voltage, but also to heat the valve.

Thanks

cdigerlando · #9 06-03-2006, 07:47 PM

Any idea which side the positive feed goes to for this application? It would be the blue wire. My clip came apart when removing it, and I'm not sure which goes to which side. Blue to the center of the motor, or to the driver's side?

Thanks

Chuck D.

Trevor · #10 06-03-2006, 07:48 PM

Quote:

Originally Posted by cdigerlando

Now that makes sense to me. Thank you for the clairification. I guess the only way to test the operation is to not only apply the voltage, but also to heat the valve.

Thanks

No. What Jason has described so well, is exactly correct. The valve is in effect a thermal delayed operate device. Applying the voltage heats the element which then responds but only after a set period. Engine heat may ultimately assist, but is not the primary signal.