My truck was running and starting just fine the other day and it was due for oil and fuel filter change. I changed the fuel filters using the Motorcraft FD4616 filters like normal. I cycled the key 3 or 4 times like normal to pump fuel back up to secondary bowl. When I went to start it I noticed it started real sluggish like it was building fuel pressure but after a few seconds it was fine. I drove it a few days and all was good until the other morning I went to start it and it was about 48 degrees out so it cycled the key a few times and let the glow plugs warm up and it started sluggish again until it built up pressure. I can shut the truck off and go back out an hour later and pull the secondary filter cap off and the bowl is empty. If I turn the key on and let the fuel pump run until it shuts off, the truck starts like normal. The strange thing is once it starts, it runs perfectly fine and has good power. I have pulled both filters back out and checked them for placement and everything looks normal. Does anyone have any ideas what could be going on?