2002 F350 7.3 Diesel won't start when engine is warm

[Weston17]

Hi,
I have a 2002 F350 7.3L Diesel.
It will start fine when the engine is completely cold. Once warmed up and shut off it will not restart. (it only does this sometimes, not every time it is shut off)
If I shut it off and try to restart right away, it will start, but if I leave it 5-10 minutes it won't. When it doesn't start I have to let it cool off for 30-60 minutes before it will fire again.
Replaced the CPS, didn't fix it. Took it to a shop where they replaced the ICP sensor, IPR and all 8 injector O-rings. Still the same problem...
Any ideas?

[Weston17]

Forgot to mention that after scanning for codes the only code that comes up is ICP low. (even after the ICP sensor was replaced) The shop also performed a cylinder head pressure test and it came back at 2000psi on left head and 3000psi on right head. (This was before they replaced the injector O-rings)

[jesilvas]

Sounds like some HPO issue, but idk what it'd be.
Probably need to monitor PIDs while it's cranking but not starting.

[Weston17]

The problem being that every time I go to the mechanic the truck will start just fine. We have tried to make it not start while I'm there, but no luck. It leaves me stranded everywhere else, but it won't do it when I want it to...