I believe that my fuel pump may be starting to fail. It is in the beginning stages of the dreaded GM fuel pump whine. I know someone out knows the factory PSI for the system. Car is an '01 SSEi. Appreciate any help.

48-52 with the car not running, all air purged out of the gauge line. This is the max pressure reading after you've clicked the key on and off a number of times.

My suggestion would be to do this after you have been running the car and it'* up to temp. While it'* a bit of a hazard for the heat and gas...it'* about the best time from a pump perspective.

Another method is to disconnect the vacuum line and it should be about 54-58 psi with the engine running.