My 92 300E Mercedes Benz will start and run for 30 sec and shut off I have to prime the filter by turning the ignition off and on like 3 times before it will start again Any solutions?

The problem is with the fuel pump control. When your turn the key on power is applied to the fuel pump for about 1.5 seconds, and the pump continues to run during cranking. After cranking the operation of the fuel pump is controlled by Engine System Control Unit (MAS). The MAS receives RPM info from the ignition control module to determine how to control the fuel pump. Their are some tests that can be run to determine the exact issue. If you message me your email address I would be more than happy to send you a PDF of the procedure.

Hope this helps.