I would say you need to check out your lift pump pressure when not starting, like someone else said, open your water drain on your fuel filter and make sure you have flow and if you do, then you can check pressure by removing the eighth inch pipe plug on the top of your filter housing and hook up a mechanical oil pressure gauge to that port. Once again turn key on with drain closed and see what your pressure is, Im not sure of exact pressure for your vehicle but should be at least in the 20s or so

 

Are you building rail pressure while cranking? Lift pump pressure?