My truck will start then it looses power and turns off. When I check the fuel pump it is running but no fuel is in the filter? Can anyone help?

On diesel engines that will not restart, after they are warmed up, it's often a sign of a tired fuel pump. As they heat soak, inside pump head clearances increase and it will no longer develop sufficient fuel pressure at cranking speed. While it's running, fuel helps cool the pump by carrying the heat away. I would only install a new Motorcraft fuel pump; i.e. no aftermarket fuel pumps.