changed pushrod side cover gasket and front cover gaskets last weekend due to oil leaks . to do theses gaskets i had to remove the vp 44 . when i finished the gaskets and tried to prime the vp 44 had no issues .when i primed the injectors with 135 fittings cracked it took a very long time , cranking on for 30 seconds and off for 1 min repeated for about 20 minutes untill injectors would prime . all crush / sealing washers were replaced . my problem is that after sitting for 6 hrs or longer the truck doesnt fire right off it takes about 20 seconds of cranking to fire . when it does fire all is fine plenty of power 14.75 # fuel pressure after filter wot and 20 # boost . I am lost and dont know what could be causing this issue other than the vp 44 . this is the 2nd vp 44 on this truck and it currently has about 250,000 miles on it and has been supplied with 14-15 psi wot since it was installed under warranty at 97000 miles . any help with this issue would be greatly appriciated

 

Possibly you have air getting into the fuel lines while it is sitting. Did you use aftermnarket crush fittings or Cummins? I had problems with aftermarket crush fittings, specifically the ones that Midwest supplied with my VP44. When you compared the two, they were not the same. I ordered a set from Cummins and the problem went away.
If you believe that to be good, I would take a good look at any connections that may have been disturbed from the fuel filter forward..gm

 

yes the crush washers on my supply side are cummins and looked identical .the crush washers on return side are aftermarket and appeared better than oem .just to update i have no issue when using the block heater . i shouldnt need it here in the central valey of california . so im leaning towards the grid heaters .