02 F-350 won't start, unless hpop primed

[FarmerJW]

Well I had to make a new user name could not get on my old one. I've been having a few problems with my superduty. It will not start outside when it is cold unless I put oil in the hpop resivor. In the heated shop it will fire up for about two mins. then it will start chugging i.e. ICP will drop. Clears up and runs fine. After that it will run all day with no problems even turning the TW program up reaches 3000 PSI, unless I let it sit for an hour then it starts all over again.