have a NA 1990 300zx that doesn't seem to be getting fuel past the fuel pressure regulator. I just bought a new pressure regulator and installed it in hopes that would fix the problem but it still doesn't have any pressure past the regulator. When I got the car just about all the rubber in the engine bay was dry rotted so I have replaced all the vaccum, fuel and water lines. I also did aiv, prvr and egr delete to simplify the engine. I have the vacuum line that goes to the FPR going to the plenum as instructed in multiple forums I have read for doing the aiv and prvr solenoid delete. Only thing I can think is that the plenum isn't creating enough vacuum to open the diaphram in the FPR but i dont know how to fix that. I can spray starter fluid in the plenum and the car will start up till it burns off the starter fluid just so you know.
My car has a manual transmission.
The fuel pressure regulator will regulate the fuel pressure by allowing fuel to return back to the fuel tank if the pressure gets too high. If the fuel pump never produces enough pressure and volume of fuel to run the engine, then you need to replace the fuel pump and filter. The vacuum line on the regulator should go direct to the intake behind the throttle plates to work correctly or you will get too high of a fuel pressure when the pump is working.