This sounds like a classic case of a worn airflow sensor pot. The wiper inside the pot wears out at the normal idle position and the ECU loses input for a second causing a stall.

I had the same problem with my '88 260e. It would stall while idling or coasting to a stop. The pot is located on the front of the air flow sensor and has three wires going to it. It can be replaced but MBZ does not sell the pot separately. I purchased one through Olyparts.com.

Do a search on airflow sensor pot and there should be a lot more information on the subject.

There are many more causes of stalling and hesitation but if your car still has the original pot there is a good chance it is worn out.

John