The odd thing is that when I installed the primer pump two to three weeks ago, I pushed it once and it immediately filled the pre-filter and, I assume, the lift pump with fuel. The fuel, unfortunately, was full of crud, so I bought another pre-filter as a replacement. When I swapped them out a couple of days ago, pushing the primer pump would not even fill up the pre-filter. Why would it hold prime for two to three weeks and then, all of a sudden, not?