Hi all. New to this site. I could use some help on a 2003 Harley f150. it is the supercharged 5.4. Driving down the road the truck started missing and died. Will turn over and start then dies. I get it home and run some tests, no codes. Fuel pressure is about 40 when I turn the key on but when I start the truck it drops to zero and dies. I can hear the pump running. I replaced the fuel regulator and ruled out issues with relays. Ultimately I changed the pump assembly. Long story short, the truck has fuel pressure when the key is in the run position. When I start it, the pressure drops to zero and it dies. once the truck dies, the pressure goes back to 40 ish. Does anyone have any ideas? I am stumped.