I'm working on a 6.0 powerstroke 2004 250 superduty. It won't start hot and long crank period to start cold, I have replaced oil tubes to oil rails , have had all injectors out and checked d ring seal all seem good , I have replaced plug in hpop (earlier problem) , worked great for 3 weeks , now won't start hot, rechecked discharge line at hpop doesn't seem to be a problem , when running engine runs great , have replaced oil cooler and did a egr delete , ( install kit.) wires have seemed to have gotten hot in injector harness due to exhaust leak , and soot on control module due to earlier exhaust leak. Still seems like internal oil leak is the problem ,going to pull valve covers and check seals on oil manifold plugs , is the any other place these things can develop internal oil leaks in high preasure oil system.. or could this be a injector control module problem .

You have done a good job of covering the bases. Verify the oil pressure with a known good mechanical gauge. The link below may help:

https://www.askmehelpdesk.com/cars-t...ml#post1415281

No start hot. Remove the Injection Control Sensor (Located by the Glow Plug module Right Tappet cover) Check that when cranking you have oil pressure. If no oil pressure here check the following:
Remove tappet covers, start vehicle with engine start, check for excessive oil flow from the Oil Distribution Rial on top of Injectors. If you have too much oil leaking vehicle will not start hot. Remove the oil rail and check the oil rail to injector tubes, u need a special tool to tighten the swivel type nut. Re fit and check again. If it still fails to start, replace injectors that are leaking.
If you have no oil pressure at the Injector Control sensor, the HIgh pressure oil pump could be at fault, the tee section o-rings. Ensure when cranking engine you get oil pressure at the gauge on the dash board.