c4500 losing prime
 

hi guys new here . I have a 2005 c4500 just bought few weeks ago . truck ran fine until about 150 miles then went into limp mode code 1093 . would shut it off wait awhile and would start up then get a few miles then limp mode again . would stay running . so i changed filter . Got 130 miles limp mode. so i changed the filter head and FPRV and fuel pressure valve with a race valve . now when i prime it it starts then losses its prim . even if i don't start it i can prime the pump up hard as a rock then what 30 seconds then its soft again. It held its prime before i changed every thing. i dont see any fuel anywhere. i ran a few tests pressure the fuel tank and seen no leaks . I took off hose off the side from the fuel filter housing going to the cp3 and put 5 pounds of air to it and i could hear the fuel in the tank gurgle. Im sure this isn't right .