Fuel Pressure issues? Intermittently runs rough, no starts, and then ok

Ok, so I installed the new fuel pressure regulator, not much change. With the relay in place the fuel pressure varied between 25 to 30 psi, the only difference here is the fuel pressure increased on acceleration. With the relay jumped to "high" fuel pressure maintained 40 psi, no movement on a 10 mile spin, speeds up to 65. A few days later started it up and fuel pressure was reading less than 5 psi. I took that as good news as the intermittent nature of my problem seemed to return. Jumped the relay to "high", fuel pressure still reads less than 5 psi. Using Rainmans post Tundra wiring diagrams ( https://www.tundras.com/threads/ultimate-tundra-wiring-diagrams-collection.81448/ ) I took out the drivers side seat to access the BB1 connector and fed the fuel pump with 12 volts from a battery charger. Fuel pressure still under 5 psi...reversed polarity a few times as other posters have suggested to unstick the fuel pump....no go. So I'm thinking as Festerw and Shifty have suggested its time for a new fuel pump.

PS Thank you Rainman for those wiring diagrams. They're fantastic.

 

Loop back and let us know if the fuel pump solves it, please. This sounds like the fuel pump is dying to push fuel, and I've yet to see a single member whose fuel filter or fuel pressure regulator has gone bad/clogged, so I'm 99% confident those weren't it.

I can't recommend enough going with a Denso replacement pump.