Occasional long crank problem

It’s a long crank. But even when it’s slow (like after cold weekend that we had) if hand primed it fires up after couple cranks.

 

Replaced the check valve for on Davco housing but nothing really changed. Probably next step to pressure test the fuel system...

 

Happening for the past few months. Different fuel, added Lucas - no effect , few filters changed several times, check valve on head, check valve on Davco, primary fuel filter housing ... WTF how injector could be leaking but truck pulls great, no bubbles in fuel tanks, balance test good, ran this week with 6.9 average mpg with when idling shows 0.5-0.6...
Sounds like if I had electric pump like on Cummins when you turn ignition on I wouldn’t even notice a problem