Ok, I am rebuilding the fuel system on my LB9. First, I got new injectors from South Bay. On first pressure, one injector leaked badly. Pulled it all apart, moved a couple injectors around, seemed to fix the leak. There is not much that holds that injector on the seat...(how does that o-ring hold against 40+psi?)... But it seems to be holding pressure.

I put in an adjustable reg from South Bay. With that disc in the cover, my lowest pressure is 48 psi with the screw just about out of the cover. I believe this will be ok. thoughts?

But when i kill the pump, pressure quickly drops from 48 psi to about 20 psi. Then slowly bleeds down to 0 over the next minute..... So am I dropping the tank to replace the pump now?

Given that these injectors are new... I am guessing the only thing that is relieving the pressure is the check valve in the fuel pump.....

Anything I am missing?

 

Try to pinch-off the fuel return line near the front of the engine and watch what the fuel pressure does, this will isolate the fuel return and then you can decide if the pump is not holding pressure.

Good luck.