I see your post has a number of viewers but no takers. I agree your problem seems to be fuel leaking off while the engine is not running. As I am not a bonafide Deere Man, I don't know every version of every model by heart, so I'm forced to look at the pictures. The parts pages I visited show more than one possible fuel system, of course, and we don't know which of them is yours. All those I saw show an electric pump. One version shows it mounted below the fuel filters, with hoses routed so fuel is pumped from the tank through a check valve and into the primary filter, to the pump and under pressure through the secondary filter to the injection pump. All the others show a pump mounted in the tank, which supplies fuel under pressure throughout. I did not see a check valve listed anywhere with the internal pumps, so I suspect the pump has check valves built in, which could be your problem. I would suggest you open the bleed vents on your fuel filter bases on your next attempt, turn the key on and see what happens. If it's true to form, you will soon get a spurt of air and then fuel from each in turn. Close the vents and try to start the engine. It should start far quicker than it has been. You might also inspect the fuel lines for condition and hose clamps for tightness, as any air leaks will contribute to fuel bleed off. If everything external looks airtight, you might consider pulling the pump out for inspection, assuming you have an internal pump
