As I re-read your issues, I agree with the other fellas. Your pump diaphram sounds weak. I installed a new pump and when I spin the starter, fuel shoots out the bleeders with force. I have also had injector pump racks to freeze up with rust on new project tractors I take in. Take the cover off the side, spray with penetrant and use a vice grip to slide it until it slides freely.
Watching your thread. Good luck.