Hard to Start

I have a 2002 Olds Intrigue 3.5L with 101K miles that is hard to start (must crank several times before it starts). I have replaced the fuel filter, crankshaft position sensor, and the fuel pressure regulator (there was excessive fuel in the vent hose). The car started perfectly for one week after the fuel pressure regulator was replaced, then the problem returned. I no longer have fuel in the vent hose on the fuel pressure regulator. A neighbor suspects the problem is a defective fuel pump. He brought over his Snap-On fuel pressure guage, and with the engine running, I'm getting 35 PSI (a low reading according to this forum). When the engine is turned off, the guage drops to zero within ten seconds. Could the new fuel pressure regulator possibly have gone bad? (The replacement was an AC Delco). Is there a diaphragm or check valve within the fuel pump that could have gone bad and is allowing the fuel to bleed back into the gas tank? I'm a newbie to this forum and any help would be appreciated. Thanks, Biodan955