in my RX with the defrost on it runs 2k RPM, I think this is a bit high. what does yours idle at? and is there a way to lower it? I know it kicks in for the AC but I'm not running the AC right now and 2K it still seems a bit high even for the the AC.

I've got mine ('87 RX) set at factory spec (600rpm I think), turning on the A/C (or defrost when the A/C compressor is cycling) will bump it up about 200 more. My AAV works fine on cold start, but there is a point about a minute after start when it will idle as high as 2500rpm, then it slowly proceeds to normal as it comes up to temp. I dont think there is any adjustment for the AAV, maybe I should put a restriction in the AAV line to the manifold, I'd like to keep it under 1500rpm. Drivability is good right off the coldest start so maybe I'll just let it be.

 

Sounds like your AAV may be holding open, have you checked the circiut and coil resistance? Try pinching off the line from the AAV to the manifold and see if the RPMs drop.

 

Gary

Yes the fast idle speed is adjustable, took me forever to figure out what this set screw was for, go here for a picture of where it is on your manifold:

 

http://www.ultimatesubaru.org/photos/showphoto.php?photo=2783&sort=1&cat=500&page=1

 

You do have a turbo motor in that RX right?

it idles fine untill you turn the AC/defrost on then up to 2k. and yes this is the 88 thats stock