e30 325ix idling issue?

[zfever]

Once I start the car, the idling goes up to 1 1/2 rpm and then back down to 1 consistantly, just back and forth, and it wont stop even once its warmed up. Have any ideas what it could be? It just started doing it today, after a day of not driving it.

[ethirtydavid]

A good place to start would be checking for intake leaks between the AFM and throttle body. This sounds like what happens when the ICV fails.
If you have no cracks on the intake boot and find no leaks, disconnect the ICV and see if the symptom changes. If there is no change at all, replace ICV.