Is it normal for EZ-EFI idle IAC to drift?

[John S]

I have recently gotten my EZ-EFI running, and all is well EXCEPT the IAC at idle seems to drift. With a warm engine, I set idle IAC to about 20, then drove it around for about 15 or 20 minutes. The idle IAC had dropped to 5, so I set it to about 20 again and drove it around for a while again. It dropped to 5 again. Since I'm new to this stuff, I'm not sure if this is normal or not. Do I just keep adjusting it back to 20 until it stays put, or is this an indication that something is amiss? If there are other readings that I should provide to help with sorting this out, just let me know.

[whizkidder]

What was happening with your idle speed? Always higher than set in the handheld?

[John S]

Thanks for the response. No, the idle speed was always what I set, which is 850rpm (a little high, but I'm in the "don't know what to expect" mode, so I thought I'd start with a fast idle, then slow it down once my confidence builds.) Since the IAC drifted down as I drove for 15 minutes or so, I would guess that continued drift would eventually result in the idle speed increasing, but I have always changed it before that happened.

[bbtim55]

Mine does same thing. Runs fine hold a idle no problem. Only having a hard time with cold starts. I have to give it gas for 10-15 seconds hen it hold idle fine...

[fridgeguy]

My cars do the same as well. I think that as the engine warms it needs less IAC to idle therefore the IAC drops.