This may sound a little crazy, but the banjo coupling into the injection system (line from the tank to the injection system) may have a clog in it where it goes into the injection syst. take the bolt loose and see if you have good fuel flow, if not run a wire into the line (back towards the tank)...see it that helps, if not, back blow with a compressor on it till you hear bubbles in the tank(take the fuel cap off first)...Hope this helps...I replaced fuel filters on my 6000 and it was the above,,, once I took the line loose, just a small flow came out...when I hit it with the air hose...mucho fuel started coming out...be ready to turn off the fuel at the tank...BobG in VA