Manual pump VS stock, does computer regulate fuel at pump?

The PCM only turns on the fuel pump via the ASD relay after is has a cam and a crank signal from the sensors. It will turn on for about 2 seconds when the key is first turned on then turn right back off. This is just to keep prime in the fuel system. Fuel pressure is regulated by the pressure regulator located on the top of the pump itself. It is a return less system. There is no loop (return line) like early fuel injection systems had.