he has 613 psi of icp. check fuel pulse width and sync while cranking. You do have a hpo leak but it should still start.

 

He was at 600 rpms on the numbers he gave. I bet it's not an oil rail issue. Looks like it's HPOP time. I've seen many hpop's act like it's running out of fuel. Which is what was going on when 1700 rpms is the max. And at 600 ICP and 84 Ipr,, I would air test with the oil filter unscrewed almost all the way out. NOT all the way out,, Because it might volcano oil out.

 

I pressure tested it and did not hear any leaks so I stripped out the whole top of the engine and there was air bubbling through the oil cooler, I ordered a new HPOP, put it in and its still doing it but not as bad so I removed the HPOP and put 110lbs of shop air in the top of it and it was coming out the bottom of the pump a small amount. I sent the pump back as defective and they sent me a replacement which is doing exactly the same so I'm trying to find out if the pump is meant to do that or not as I believed it wasn't supposed to let anything by it.
I just cannot see how a pump is going to provide 1000's lbs of pressure if 110psi is getting past the impeller so I'm trying to find out if I'm right or wrong before I call ForDiesel again to send this second HPOP back since they don't seem very nice on the phone like I'm just hassling them.