what should the fuel pump pressure should be? on 1997 Mercedes-Benz E320

the car would just stop; and has no fault code. I changed out the crankshaft sensor, and the car did the same.
I changed the fuel filter because it was hard to blow through. I checked the fuel pump pressure; it was 70psi, but will change from 70 to 40psi. is this normal?

1 answer
fuel delivery should be 1 Liter in 35 secs or 3.2 to 3.6 bar. google bar to lbs and convert