There is no need to Bleed the system, they self Bleed, these systems run on very High pressure, is the pump damaged re - any "debre"..."rust"..coming through as the tanks rust in the inside, over the years, To test pump pressure this is done at the 5th injector this is on the main pressure line,...remove pipe...rig up pressure gauge..Bridge on pump relay terminals 30 / 87 pump runs all the time, you MUST see 85/90 psi....The reason i write this is with a Fault or not in the metering head, as soon as you crank engine from Cold the 5th injector is on a TOTALY independent circuit, so with pressure sprays neat fuel into manifold...so with 4 good sparks on plugs...it should have burst into life...if only for a 3/4 seconds...then stop...your not getting that ?..im thinking put the old Filter back as a test...also some after market filters have "in & out" as to flow..worth a check. Peter.