When adjusting the idle on an 89-94 EJ22 is there a certain way it has to be done because of the throttle body screw and IAC adjustment? Or do I just set the IAC near the factory (paint dot) position and then fiddle with both the IAC and TB screw positions?

 

Umm, in other words. If there is a special way to adjust the idle, what is it?

 

Thanks

There is no idle adjustment! Done entirely with the ECU. Usually, cleaning the IAC will fix your idle problem.

 

By the way, don't muck with what looks like an idle adjust screw. It will only make the problem worse.

There is no idle adjustment! Done entirely with the ECU. Usually, cleaning the IAC will fix your idle problem.

 

By the way, don't muck with what looks like an idle adjust screw. It will only make the problem worse.

That's what I figured.. I set the screw back to where it should be (aka, idle "switch" is reading off when off and any throttle and it's on.) I think I just have a dodgy IAC.. But we'll see..

 

So don't touch the setting screw then? Or rotate the IAC? Why can you adjust them then?

The screw doesn't adjust the idle - it just adjust how low the throttle is allowed to go.

 

Say for example that the throttle's position range at stock is 0 - 100%. With the screw, you could just the throttle position range to 5 - 100% therefore effectively "raising" the idle - but all the ECU sees is that somebody is pushing on the gas pedal a little.

Well I'm getting my random code 24 again.. It idles fine now exept sometimes when driving the CEL comes on and then if I put my foot on the clutch or pop it into neutral the car's idle drops to 400-500 and then in some cases stalls. If it doesn't stall the CEL goes out and idle returns to normal. I'm going to see if I can test drive it some more today before I swap out the IAC wit hthe one I got from the wrecker.

Sorry to bring this up to the top but I just wanted to add the final solution to the problem, read the posts in this link:

http://www.ultimatesubaru.org/forum/showthread.php?t=71100&page=17

 

The IAC code 24 just stopped happening one day. But the idle was still screwy.. But after I fixed the VSS code 33 the idle is now good as well as everything else.