The first thing I would do is check the screen in lift pump, then remove the banjo bolt and fitting from the inlet side of said pump. Remove the fitting completely from the hose, then inspect all of those components for debris wedged into passages. If that's all clear, then using a jug of clean fuel and an adequate length of fuel hose, set up an auxiliary supply to that same fitting. Bleed it out again, start it up and see how long it runs.