A 380sl I've been restoring had a surging idle. So I had Programma rebuild the idle control unit, which cured the surging.

However, the car is now idling in gear at around 1000-1100 RPM's, rather than in the normal 600-700 range, and tweaking the potentiometer on the unit doesn't seem to do very much.

So I was wondering if anyone here could tell me what that potentiometer is supposed to do, if not somehow increase and decrease the idle.

Thanks very much in advance.