It is the HPOP that was in it when I got it, I haven't changed it, I only took it out to check it, and put a new gasket on it, and the oil pressure gauge will go up to half way when it is cranking, so I don't think there is an oil pump issue, I have a 5000 PSI gauge screwed into the right cylinder head, and after I pull started it, it was idling with 600 PSI, and went up to 2000 at 1500 RPM

 

if you dead head the pump, you should see 2500 PSI.


2000 might indicate a leak. a leak will cause no start.


I think pull starting made engine spin faster with more flow to start it

 

Maybe when you reinstalled the HPOP, something happened to the check valve or whatever it is that prevents the reservoir from draining back down into the pan. But that would only tell half the story; wouldn't explain the zero injection pressure after filling the res. Something about the higher RPM while pulling it, the answer is there somewhere....

 

you pulled the HPOP, there is air in the system possibly pushing the oil out

 

This ^^^ makes the most sense to me.

If the res. drained out, then when he turned it over the pump put air back into the oil rails. So basically its like he just pulled the injectors and its all full of air. Fix the res drain problem, get it running again and you should be good to go.