Ah-HA! I have this problem. Warm, cold, it doesn't matter. In gear in neutral, any gear really, it doesn't matter. It has been going on for 500 miles. Other than the cyclic rpms just off idle, this 1992 car runs very well. The crush mod has NOT been done.

At VERY slight throttle settings (think just off idle) the RPMs will DROP, then increase to just above idle RPM.
IF you hold the throttle in this position the RPMs will up/down about 300 rpm about 1x per second.

I'm pretty sure this is a TPS problem in my case.
It may be a dirty intake.
Other ideas?!


Thanks, Stephen