Probably not going to be very popular for this, but I just had another look at the schematic and ...Now you have introduced a second relief valve for fuel delivery and it now bypasses the pump, I have a suspicion that you don't need the original relief valve, which relieves back to the tank.Again, releiving back to the tank might stir up the crud in the bottom.
I'm plumbing it so it goes back in just before pump so it should loop when the nozzles shut
Not that above,where did that come from?