Fuel pressure not holding

[PaulRV6]

Haven't started the engine for quite awhile and when turning on the key the fuel pressure goes up to 45 psi and then drops to zero. Is this the fuel pressure regulator not doing it's job or are all the injectors stuck open? I think they are 36 lb injectors with a KB regulator. Thanks
Paul

 

[John Larkin]

There is really only one way to tell. Find a spot to crimp off the return hose, probably above the rear axle is the easiest to get to. If the pressure still falls, it is likely the hose connector to the sending unit in the tank. PIA to drop but only takes about an hour total to check.

 

[BEATAV8]

It’s not unusual for a regulator to leak down after the pump shuts off.

 

[PaulRV6]

Does it really matter then if the regulator leaks off? Mine is made to come apart, so is it worth trying to fix it? Thanks