There is a serviceable gasket (from MB dealer ?) for the fuel distributor shaft, if your replace this the fuel leak will stop if it is coming from the shaft. You will need a special tool like a split screwdriver to open the screw because the shaft passes thru the screw. Also you will have to exactly note down the length of the shaft with respect to the outer frame because turning the screw that allows you to replace the gasket also alters how far the shaft drops when you hold the distributor in the right (up/down) position. Take your distributor to a dealer's part store and they may loan you the tool and you can change the gasket right there and return the tool.

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Saumil S. Patel