Toyota Repair: 1994 Toyota 4 Runner SR-5, fuel pressure regulator, toyota 4 runner

Question
I have a 4 Runner, with a V-6,  3.0 engine which is flooding.  If fuel pump is unpluged and crank engine it will start for few seconds then quits.  When reconnecting fuel pump engine will start and reflood then quit. just replaced fuel pump new and number 4 and 6 injectors.  Could the problem be the fuel preasure regulator, Or do you have any other suggestions.

Any help would be greatly appreciated.  

Answer
Yes the problem could be the fuel pressure regulator, it could also be a problem with the computer which controls the injector duration ("on time")there could also be a restriction in the fuel return hose to the tank, just out of curiousity, why were the injectors and fuel pump replaced?