[Adran]

On my plastic radiator guard, there is a very specific sequence that is called for to set the idle speed, which involves disconnecting the IAC valve, holding the engine at 2000 RPM for 60 seconds, and then making idle speed adjustments within 120 seconds. My question is, what is the advantage of following this procedure to set your idle speed instead of simply turning the adjustment screw until you get your preferred idle? Is there some other function I'm unaware of that the method on the emissions sticker provides?

The thing is, I'm having trouble getting consistent results out of the recommended method. It says that if you set it at 900 RPM with the IAC unplugged, it will automatically set itself to roughly 1000 RPM after it's reconnected. However, many times it seems that my idle ends up a bit too high. I'm tempted to fine-tune it afterward with the IAC connected, but I'm afraid this will somehow mess the adjustment up.

 

[UnexplodedCow]

You won't be able to tune it with the IAC connected because it takes care of idle air on its own, independently of any mechanical setting. It's electrically controlled. If you unplug it, you shut off the electronic control, and can tune manually.