According to my "Model Year 1984" MBZ manual, which has a good overview and troublshooting section for the KE system the "airflow position indicator", which is, I believe, the same device referred to in this thread as "potentiometer" is part of the acceleration enrichment system, and I cannot find any other function that it supports. The device provides a rate of change signal.

Further, acceleration enrichment is CANCELLED at coolant temperatures of 80C and above, so the device serves no function that I can see once the engine is fully warmed up.

I bring this up because it doesn't appear to have any relationship to the original subject on duty cycle, and if the device is not functioning properly it should only affect acceleration response during warm-up.

Duke