Something to check is there is a small piece of rubber fuel line in the tank that goes from the electric pump to the tank outlet mounted on top. JD uses a non submersible fuel line that swells the outer rubber coating causing it to split and cause low fuel pressure. The replacement line in the parts diagram that JD uses is also not rated for being submerged.
If you decide to go the route of actually using the submersible rated fuel line that is available from auto parts stores, be aware the stuff is expensive. Comes in one foot length and cost in the neighborhood of $32-36. The other problem is you only need about 2-3 inches.