After a extended vacation the 300Se 103 engine refused to start . i removed the cover of the relay and pushed the inner relay contacts together ,instantly the buzz of the pump was audible ,even the ignition does not have to switched on . relay replaced .
For utter reliability of the `103 engine i have found it is best to replace the following ageing and worn out components .

fuel pump relay ( initially as stalling problems )

fuel accumulator ; ( hot starting problems)

all the old fuses ( intermittent electrical problems )
OVP (cold start problems ,ABS light )

replacing these makes the car very reliable .
mak