Do you mean an MD7A? If so, I have one of those. It is a PITA to bleed the fuel system. You need patience and probably someone else to help you. Start all the way back at the fuel tank
and carefully bleed the air through the fuel filter
, the manual pump (which you've bypassed?), then the bleed screws on the injection pump in the correct order (I've attached a page from the service
manual, if that helps). If you can finally get fuel with no bubbles coming through bleed screw number 3, you probably won't need to bleed it at the injectors. The interior
of that CAV injector pump
(unless you have the Bosch :-)) has a lot of space that needs to be filled up with diesel fuel.
I went through this once for two days and eventually found the valve at the fuel tank
outlet was clogged with sediment. Once we got that cleared, it took us another several hours to get the system bled and the engine
running. That was with a diesel mechanic
Now that I've done it once more (after running out of fuel) with a buddy at sea in the middle of the night, I realize you've just got to follow the manual and be bloody methodical and patient.
Of course, you may have done all this already. If that's the case, I apologize for not answering your question about the proper psi for the fuel pump
. But mine runs fine off the little OEM manual priming pump, so it doesn't seem like the engine would need much fuel pressure.