Hello - I have a 1988 Mercedes 300 SEL. This car will sstart up and run like a champ. After about 5 Miles it will suddenly die. There will be no power from the engine at all. The tach will drop to 0 but all of the auxiliarys will stay powered up.
I replaced the Fuel Pump relay, ran the car and had the same result.
I then replaced the 10 A fuse in the OVP, same bad results.
I tested power at the fuel pump:
When it is runnning there is 13 V across the terminals,
When it is dead there is 0 V across the terminals.
Three months ago I replaced the alternator that was putting out about 4 V and the fuel filter.
I have spark at the plugs, and replaced the fuel distributor solenoid (EHA?).

If anyone knows the fix to my problem I would be greatful for their input.