im really stumped on this, been working on it a while, got the truck which was said to be running fine when it was parked a few months ago, tugged it home and couldnt get it to start, batteries are in good condition, also have my car jumpered onto it while im cranking so its cranking fast, right now i have a rag tied down in front of the intake, i can spray ether into the rag and it will start for a min then die, so its got compression, changed the fuel filter and bled all the air out of the line, havent tested the fuel pressure but im getting fuel spraying out of the fuel filter and have a steady stream coming out of the schrader valve, so im getting fuel up to the injection pump, i unscrewed all 8 lines going to the injectors and they are all bone dry while cranking, i checked the fss and that was working or clicking so i assumed the injection pump was bad, so i bought a used injection pump that only had about 10,000 miles on it and was running perfect until the block suffered cavitation, installed that one on my truck and still the same symptom, after lots of cranking still bone dry at the injectors, again the fss is clicking and sounds to be working right, if i unplug the return fuel line on the brass fitting on top of the injection pump, while cranking it will slowly dribble fuel out. I am at a total loss as to why im not getting fuel, hoping some one here might know what it is, my tanks are half full, so its not starving for fuel.. what else is there