I would then leave the plastic one there for the time being, but add an additional one in the line before the pump...
My thinking is there could be junk accumulating in what looks like a new pump....and the filter placed before the pump would trap this...
There should also be a filter sock on the bottom of the fuel pickup on the sender unit in the tank....
If the particles are coming thru as you describe, the sock may be missing...
If the particles are numerous, you may have a rusty tank...if thats the case, and others will chime in with other remedies,,,,I would replace the tank, but before installing it I would run a protection process on the inside of the new tank...there are threads on the board about this process....
