Idle adjustment problems

[poorpake]

I apologize in advance for this long post. Please bear with me.

OK... the basics;
1993 legacy (ej 22) power plant installed into a 1985 Vanagon (manual).
The engine was rebuilt by CCR and runs really well.
30,000 + miles at this point.

I have used this forum to track down and fix all sorts of little problems over the years. It has been an INDISPENSABLE source of information.

Current problem;
Upon start up the engine will rev. high (1200-2200 RMS) and then fall/ rise erratically. The RPMs will drop suddenly and the engine will usually stall. I can keep the engine from stalling with some fancy foot work on the gas pedal. Once on the road it runs really well. It usually has a nice idle once everything is warmed up. But if i turn off the engine while running an errand for instance, the problem shows up again when i start up.

javascript:emoticon('')Mistakes were made ;
BEFORE ALL OF THE ABOVE PROBLEMS....In an attempt to fix some fast idle issues i had months ago i adjusted the set screw located atop the throttle body (throttle stop screw??) thinking this would help. It did not, as you probably already know. I adjusted the IAC as well to in an attempt to reduce the fast idle at start up... that only complicated matters.

So i think my well intentioned but misinformed screw adjusting is at the heart of the erratic idle/ stalling problem. Can i get advice about returning the screw to the correct position? Is there a work order i can follow to get the screw and sensors back into position?

thanks for the help

b

[Cubson]

Hi poorpake.

It could be your Air Idle Control Valve (ICV). The valve is located to the left of the main air intake at the throttle and has a grey plastic solenoid cap.

There is a 3/4" (?) tube that essentially sucks in air from the main air supply line at idle, bypassing the throttle intake.

I have the Rocky Mountain Westy kit in my van and recently I noticed that the grommet that seals this tube had failed and my throttle intake was sucking air through the hole in the intake tube, rather than though the air filter . My ICV got dust in it and my idle went from 650 to 850-900 RPM.

I cleaned the ICV by pouring Sea Foam into the tube at idle and now it is back to working properly.

Anyway, search "cleaning the idle control valve subaru 2.2" on you tube and there are instructions on how to perform this cleaning. If the cleaning does not work, you may have to replace the ICV unit itself.

I just re-read your post and maybe you have already tried this? You should probably have a Subaru mechanic re-set the screw as I read somewhere that this is set at the factory and you should not mess with it.

Good luck.

[poorpake]

Thanks...

Indeed i have cleaned the IAC valve. Additionally, just to double check, i had a "certified" re-conditioned one installed and set by my mechanic. The problem persisted.

That same mechanic said all of the various sensors and valves were within their working parameters.

CCR said to try a new throttle body. I will swap that out next week and post results.
Thanks for the reply.

b