My car stuttered a few times then quit starting. It does turn over the starter, but when I cracked the fuel rail to see if the pump was even working there was no pressure, tightened it up and the car started and ran for about 30 seconds. That has happened twice. Could that be the pump or module? Just to throw this in the mix I replaced both vanos solenoids because one was bad and a new mass air flow sensor. Any help would be appreciated