I installed an airfoil on my car and noticed that the idle seems to jump 200 rpm every once in a while. The car had this problem before but now it seems a little worse. Is this common with airfoils? Is there something that I can do? Does anyone know why the car jumps in idle? I have been through alldata's diagnosis charts for this problem and came up with nil.

it probably has nothing to do with the airfoil... just possibly the installation. I would check the IAC and make sure it hasn't been hit around to much and that its clean and adjusted correctly. I have an airfoil and this was not an issue with mine.

That's what I figured, I just wanted to make sure. I just installed the throttle body a week before I installed the airfoil. I cleaned the throttle body very carefully and had to install a new IAC since the old one was missing.

Dumb question but...did you set the IAC properly when reinstalling? If not, you can do a search here and find out how. Sorry if this didnt help.

A friend of mine has a '97 LT1 that was having the exact problem as you. He ended up having to grind the passage through the airfoil to get air to the IAC.

Yes, I set the IAC when I installed it.
Hmmm, that's an interesting idea. I do admit, the passage for the IAC in the airfoil is rather small.

I've been looking at all the different air foils, and I've noticed that some seem to have awfully small holes for the IAC, so I've wondered about that. But I figured it's not a problem because soooo many people here have them, and I've never heard anyone complain about that.

And I just found yet a different one tonight that looks more effective than any I've seen(not that I'd really be able to tell any difference, lol), but it has the smallest hole of all of them, lol! So I thought I'd get that one anyway and just make the hole larger.

So if you do that to yours, report back and tell us how or if that helped.