Regal Fuel pressure

I have an 89 regal with a 3.1 and only 65000 miles. I recently changed 2 injectors, fuel filter, pulsator, strainer, fuel pump, intake manifold gasket, and throttle body gasket. These all made a huge difference in the car. It ran and started with ease until recently. It is hard starting (must crank many times before it will run) and seems like it is needing more fuel when you mash the accelerator(engine lopes a bit). I put fuel pressure guage on it after making the above repairs and had a steady 46 psi key on engine off and 41psi or so key on engine on. So I changed the pressure regulator today. When I tested the car I have 34 psi (key on egine off) while the pump is running but then as soon as the pump stops running pressure goes to zero. Running the pressure stay at 32-34... well below where it should be and it creates a rough idle. When I started it with the pressure guage hooked up I watched the needle slowly increase until there was enough pressure to start the car. The fue line is not holding the pressure... Before I go and drop the tank to pull out my lifetime warranty pump and put a new on in, I thought I would look for a little help here. Anything and everything is appreciated! Could it really be anything but the pump at this point? I cannot find any leaks and smell no fuel odor indicating a leak. Any input? thanks-Ken

The only thing that I can think of other than a regulator problem that would cause low pressure with the pump on and a complete drop in pressure with the pump off is a fuel injector that is stuck open.

ended up being a bad (leaking) pulsator on the fuel pressure line.. strange thing is that I changed 3 months ago when I changed everything else... all well at the very least, it is fixed!