did you put a larger throttle body than stock? if so and you didnt port match the intake mani, that can be your problem.

idle surge causes:
No coolant
Bad ICS
Bad FIAV
vacuum Leak

I bet it's gonna be the throttle body. i bet you have a vac leak at the throttle body.

And FYI a knock sensor senses knock!!!!

I bought the new ISC, the black one, and it's brand new and installed on my car.

I still have some tuning to do, but I have been just driving my car around. I still need to loosen the slack in the throttle cable , and make sure the TPS is right.

Here is what my car is doing, that is really weird (maybe someone knows the symptoms).

I have been having starter problems too, and idle surge. But, since I got the new ISC the idle surge has gone away (but at high idle due to out of tune). So... here is the weird part. Sometimes my car wont start, and when it does, it idle surges like CRAZY, untill I drive for a second ot two. Typically it will start up just fine, w/o surge.

Hmm.