I have a 2005 f150 4x4 with the 5.4. When I went to leave for work the other morning it acted as if it wasn't getting gas. After a couple tries it did start, then about a mile down the road it stalled. Acted as if it were out of gas (had put gas in the day before). Towed it home. Had stuff going on so it sat for two days. Next time i tried it it started like normal but the gas gauge read full when I knew it was only about half full. Tapped on gas tank with a hammer and gauge went to just below half. Almost exactly a year ago I changed the FPDM so I know that's good. Before I go through dropping the tank and changing a possibly failing pump, any suggestions? Fuel filter maybe?