setting the IAC

[Cleaner13]

how do you physically set the IAC

I want to try and improve my idle
I have a scan master which I am hooking up as we speak

how is the IAC set?
thanks

Carl

 

[turboculosis]

1st reset IAC:http://www.gnttype.org/techarea/faq/IACreset.html
Then set your IAC:http://www.gnttype.org/techarea/faq/IACresetscan.html

HTH...

 

[OKTurbo]

First read....
http://www.gnttype.org/techarea/faq/IACresetscan.html

You're not actually touching the IAC when you "reset" it. The only reason to actually take it out of the throttle body is for cleaning or replacement.

The IAC works by by-passing a certain amount of air around the throttle plate to maintain an idle RPM which the computer chip dictates. Most chips idle around 750-800 rpm.

With a scanmaster it's fairly easy. You're adjusting the idle air by-pass screw on the throttle body....driver's side...usually has a grey cap on it. This is NOT the idle speed adjustment...that is controlled by the computer.

You adjust the screw until you get an IAC# at idle of around 15-30. The trick is to realize that each adjustment of the screw also affects your idle TPS reading since they are attached to the same throttle plate....just on opposite ends.

You try to keep the TPS volts around 0.42 and the IAC# around 20. If your IACs are high....you'll have to readjust the TPS sensor to get a proper TPS voltage.

It sounds more complicated than it really is. It can be a PITA, but once it's set you won't have to mess with it again. If your numbers are OK now, and your car idles fine, I wouldn't even mess with it.

Good Luck,
John