My Fleetwood suddenly has been starting hard. Checked fuel pressure and it drops to 0 almost immediately after I turn the engine off. Holds 32 psi while running. If I turn the key to run a few times it doesnt really come off of 0, but 3-5 times sends it to 40 psi for a second then back down. Am I looking at replacing the fuel pump or is there something else I should check first.