To me it sounds like air in the system. Do you see any air bubbles in the glass bowel? How did you install electrical pump, as just a lift pump or did you bypass the mechanical one? If you bypass and just use the electrical one, 6 PSI is to low. If you use it as a lift-pump the capacity should be at least 100l/h. How soon after the stop can you start the tractor and do you need to bleed the injection pump? When the tractor runs dose it run OK?
Blockage in the fuel line can occur in the tube from the tank and also in the banjos. Always tricky with this type of problem but replace all the hoses from the tank to the fuel filter and make sure there is no leakage of air. At the same time make sure there is a free passage to the tank by blowing in the hose.
Hazze
