I have a 1996 GMC Sierra 1500, 5.7 vortec. I have replaced the spider injectors with mfi injectors, pressure regulator, fuel pump, fuel filter, fuel lines. Before I replaced the regulator I was getting 30 psi fuel pressure, and with the new one I get 50ish. When I pressure test the system, the fuel pressure goes up to 60, then drops very rapidly. Would that be the injectors leaking? There are no leaks anywhere else in the system.

 

or back to the tank.