When I disconnect the clamp and hose from the return-to-tank line from the fuel pressure regulator at the end of the fuel rail I notice during the 3 seconds (after key is on) that ALL gas goes out the opening. I wonder if proper fuel pressure is building on the rail side.

the Rover won't start and I smell NO gas in the tailpipe. will only start and run on quick-start.

the vacuum line going to the regulator is not connected. should I put a vacuum pump to the line and then try to start it? does the regulator need vacuum to operate?

would the injectors NOT fire if fuel pressure is too low? how would I tell?