sorry going to be long post.2001 cummins quad adr. dap 150s fass 150. installed injectors and quad about 6 months ago,everything fine until last week, towed 10000 lb trailer 100 mi fine, 100 mi back home fine, next morning no start o fuelpressure, loosened fuel filter primed fass started fine, next time to start same. i checked for leaks found none, bolt on back of head ,t back of head,all fuel lines same no start 0 fuel pressure until i prime fass. removed fuel and water sep checked gaskets installed now have instant fuel pressure on key bump and 25 sec starter bump,still have a long crank after truck sits for a while. park nose down starts fine.question can injector or injector tube be cause and still have instant fuel pressure?