I agree with alabbasi. The problem has to be in the dist. My guess is the rotor. I have never seen it on a Mercedes but we have seen a problem like this on many cars and trucks over the years. The rotor develops a hole from the center button location to the distributor shaft. It can be seen if you look very carefully inside the rotor where it sits on the shaft. It will be a very small dark spot. This is usually caused by a bad plug wire.
Keep in mind, as you are trying to start the engine the fuel system is still working which will flood the engine unless you have removed the fuel pump relay or something to stop the fuel pump. BTDT.

Good luck
Paul

__________________
84 500 SEL (307,xxx miles)