1999 7.3 oil pressure

I have a 1999 7.3 that will not start until the oil pressure gauge moves it takes at least 15 secs or more for the oil pressure gauge to move.Once it moves engine builds icp pressure but it takes a long cranking to start even after it starts and runs for a few mins and you shut it off it does the same thing.I pulled lpop and it had some wear on it so I replaced the pump it still does same thing supposedly engine was rebuilt.Truck has 150k miles and engine only has 40k on rebuild I have no idea what was done when it was rebuilt.I did replace oil pan few months ago I did the pan in truck never again pain in the ass I used the moroso oil pan and gasket.I was going to look at the oil pressure relief valve in oil cooler next the hpop reservoir is full it's not leaking down I made a dipstick out of a straw and it's right at the top.So trying to figure out where to go next I don't think it's a pickup tube issue the engine runs fine it's just the initial starting that's the problem.

Have you checked the short Circuit spring? It’s behind the hpo Rez

I think your Rez is draining also.

No I haven't I let the truck sit for a few hours and I rechecked the oil level in the hpop revisor and it was about full I will check level again truck has been sitting for a few days now.

What oil filter are you using?

live life full throttle

Sounds like an issue I had with an ipr coil but mine was only when warm. And it eventually ended up in the ipr somehow puking oil out into the valley and into the ground.