[GTJIM]

I have a feeling that you are measuring the fuel pressure in the fuel return line and not in the injector rail. I don't think a Bosch FI system will run with fuel pressure that low at the injectors - I know my Isuzu system which is based on the Bosch type, just cuts out if fuel pressure drops below 33 psi.
Found that out in traffic when the fuel pump finaly failed.