Toggy

I need to find out if my Iac is working properly, can I do that with a voltmeter? if so, how?

Thanx
/Toggy

Phobos84

This is going to be a little harder then on a crossfire like what I have. First you will need to remove the IAC. Then you need to bridge the ALDL conector. You can use a paper clip or get one of those plug in diagnostic things from Wallmart and then turn the key one click forward. This should make the IAC move. If it were in the throttle body it would plug the hole. If you have a shop book it will go into more detail about it. To get the IAC to move back it its origanal posion just turn the ignition off. This will tell you if it is moving but not if it is leaking any. Just for piece of mind I would just buy a new one. I know this is how you would check one on a L83 Crossfire only without removing the IAC because you can see it from the top. It should be the same on a L98 but I'm not sure. If I'm wrong it won't hurt anything.

Tom Piper

The easist way is to find a "bi-directional" scan-tool like the Vetronix Tech-1A, MasterTech, or Tech-2 -- http://www.vetronix.com/diagnostics/tech1a/index.html.
After connecting the scan-tool, you can simply send a command to the ECM to change the IAC position. If the IAC is working, the idle speed will change.

Tom Piper


[Modified by Tom Piper, 12:05 PM 3/25/2003]

65Z01

The IAC has a set of coil that move the pintel when the ECM sends pusles to it; so you can only test for opens or shorts with a DMM.

I like the idea of removing it and jumpering the ALDL to see it move; but be careful that the pintel doesn't fall out. Lay it on a Bounty or such before turning the ignition On.

You need the scan tool to see how many pulses the ECM is sending to position the pintel.