fuel to pump but not out

[Managerdhv]

I have a cub cadet 7272 I inherited. It has a 30 horse Mitsubishi motor. It is getting fuel to the diesel pump but not pumping out. When I crackthe adapters that the lines tighten into coming of the top of the pump it Will pump fuel but the second the line is back tight it stops. Is the pump weak? The spring delivery system in the line adapter weak? The throttle stuck internally to off to stop fuel? Fuel shut off solenoid stuck? What are best diagnosis steps to take from here?

 

[Leejohn]

What is the spring delivery system ?

 

[Tx Jim]

Welcome to TBN
Does fuel solenoid on inj pump click when ign switch is turned to on?? If it has a manual trans with no hyd shuttle you could try to tow start it.I once owned a Ford 3000 that when it was run out of fuel it was the dickens to get bleed so it would start. When I got tired of bleeding I tow it and it would immediately fire up.

 

[JRobyn]

The Cub 7200 series have both an electric fuel pump and the injection pump. Make sure the electric pump back by the tank is running when you turn the key on. You should be able to hear it "pulse" a few times. Then there is a fuel cutoff solenoid on the injection pump like Jim says that you should be able to hear click when you turn the key on. There are TWO separate power circuits involved for this solenoid; one is via a 10amp fuse in the regular fuse box, the other is a 50 amp "block" fuse plugged into a wiring connector on the driver's side of the engine. I think it's the yellow one. Make sure to check them both.

Welcome, and good luck!

- Jay

 

[Managerdhv]

I ran down the wires on the electric solenoid. The red wire does in fact connect to the black and yellow wire that connects to the starter solenoid to provide the 50 amp draw to open the solenoid. Little more info is that the key is only supplying 5 volts to the starter so therefore i am jumping the starter with the key turned forward so it is hard to tell if the fuel solenoid is actually opening. I tried jumping the fuel solenoid to verify that it is clicking but I only heard it click open when power was supplied to the blue wire which the diagram says is a ground. the white wire is getting 12 volts when the key is turned forward which is the 10 amp required to hold the solenoid open. Why would power to blue wire open it? I do not know if power to the blue wire will solve my fuel solenoid issue or not because I was unable to test it by myself. Does the fuel solenoid apply pressure to cut off the fuel and that is why loosening the adapter at the top of the pump takes some pressure off allowing fuel to flow? Also yes the electric pump at the rear of the tractor is cutting on. There is also a second electric pump near the inj pump that cuts on as well. Hopefully this gives you guys a littlle more detail.
It is a manual transmission but we are trying to avoid pull starting at this time. I am trying to run down all the tractors problems first to determine if it is going to be worth my time and money to fix. I think that the fuel delivery is the most important thing at the moment but my Dad will not come back to the shop to help until the key actually turns the starter so I also will have to be tracking down why the key is only putting 5 volts to the solenoid before I can have two sets of hands helping.
Thank you all for your responses and help.