Idle Fluctuation When Warm

[Pstallo]

Hi, this is my first real post since joining the forum a month ago and lurking.

I've been reading everything in the posts about this topic, but can't afford to replace part that's been suggested in the posts at one time without a little direction (everything from the throttle body and AFM to the oxygen sensor and vacuum hoses has been suggested)

My 1986 911 Carrera 3.2 fluctuates when idling between 800-1100 RPM every second or so, but only when warm. I've replaced the Idle Control Valve and the air filter as indicated in one post, but no change.

I've noticed that nobody with the same problem indicated what actually solved the problem--they just sort of disappear. Does anybody have a clue what the final cure has been?

In short, I can't really argue for the WEVO shifter and roll bar with my wife until she stops complaining about the engine 'revving up all the time' when we go to the grocery store.

Thanks!