Hi,
the sensors tend to fail immediately - and their behavior is dependending on the temperature. The warmer it becomes, the more troubles you have. Try to "ice" down the sensors to below 0°C and they will probably work. The V8 only needs the ignition point sensor for starting the engine (to know the upper dead center of C1), the rest is done by the engine speed sensor. So it may start properly, you drive an hour, stop the car and can't restart it until next morning
Regarding the pump: The relais for the fuel pump is not activated by the Motronic before both sensors deliver (valid) signals. It is a very common wrong diagnose that the fuel pump is broken; in fact the sensors are.
Change 'em - both of them in one go.
Best regards
Bastian
PS.: Just for fun: You don't accidentely have a friend driving a Porsche and who spent some monthes in Aalborg, Denmark two years ago?
