97 C2500 losing fuel pressure

Hi I have a 97 C2500, 6.5 Lt of course. I recently had to put a new injection pump on, new fuel filter / AC Delco filter, Timed it. Had new SS diesel PMD a while ago. Since I put the new injection pump on it idles / run for about 45 min, Then quits. I have to bleed the fuel filter to get it to start again. I pulled the intake back off to check for leaks and did not find any. Checked lines from tank to pump again no leak. Any and all help is needed and appreciated to solve my dilemma. Thanks in advance. I am a newbie here.

I went thru this recently with a difficult to find air intrusion leak.
Lines get rusty,. A tiny pinhole will let air in but in the right place no fuel will leak out,. This is very true on the "pull" side of the system between tank and pump,.
My hard to find hole was right at the sending unit right at the 90 deg bend where it comes out from the tank on the bottom side of the bend hidden from sight
I missed it on a visual inspection,. I found it when i put a hose from fuel pump pressure side into a bucket and hotwired the pump.
Very frustrating....������
Compounding my problem was the lift pump was old and didn't have enough "suck" to pull the fuel up out of the tank very well,, i put a new airtek pump on (E8153) fixed the pickup pipe, and things went back to normal. My symptoms started small and as i ignored them it got worse until after sitting 4 hrs it was a whole rigamarole to get the truck going again.
Every thing works together on the 6.5 fuel system, the injection pump will help the lift pump, but introduce a little air to the mix and both lift and injection pump performance deteriorates really rapidly,. Its a fragile system.
I have brought non running trucks home with a separate fuel system consisting of jug with feed and return and a hot wired ziptied pump under the hood.

Hi Thanks for the response, I will check that out and let you know how I make out. Thanks again, I have 255K on mine.

Are you sure the tank is venting correctly?

Yes I checked the fuel cap , ran it with it off and it still stalled after about 45 min.

I had an issue a few years ago where the fuel pickup "sock" (strainer on the end of the pickup tube) inside the fuel tank was clogged and collapsing with the fuel pump trying to pull fuel from the tank. Letting it sit for an hour allowed the sock to relax and start letting fuel flow again, only to clog again a little while later. It was very frustrating.

My symptom was the fuel filter housing would empty of fuel, and I could not get it to prime at all until letting it sit for a while, so it may not be the same problem as yours.

I had to drop the fuel tank and swap out the sock on the pickup tube.

Casey