Does warm idle setting affect cold idle setting on a Carrera Motronic?
 

I'm kind of fine-tuning now after sorting out several issues with this car, which I acquired a few months ago, and I recently had my CHT sensor professionally installed I (which turned out to be a good thing, as the sensor was stuck in the head and needed to be retapped after removal). The mechanic reset the idle, as it was idling at about 1200 (probably hillbillied-up by my PO). Now it seems too low, it idles at around 650 warm ( surprisingly smoothly) and it has now become difficult to keep running right after cold start-up. Are these settings correlated ( proportional to each other) or are they separate issues completely?

If the motor is running correctly the idle should be around 880rpm and not vary much. The computer (DME) controlled idle stabilizer valve (ISV) controls the idle speed. If it idles at 650 or 1200 something is not working correctly.
-Chris

You may want to reset your idle, if you CHT was off last time it was set, you may have to return it to normal before raising the idle back to normal.

Check the mixture with a gas analyzer before messing with the idle setting. If the mixture is off just a tad, it could be affected by temperature changes.