Tractor Repair: john deere 310a

Question
tractor run find for short time then start losing power and stalling ,if i lose or remove the bleed screw on the injector pump power returns instantly and runs find for 10 to 15 minutes please help

Answer
 Check that there is good flow of fuel from the tank.  If there is a restriction, it can't supply enough fuel to keep up with demand.  If there is a lift pump that pumps fuel to the injection pump, make sure it is working OK.  Possibly the return line from the injection pump has a restriction.  It is common for a plastic governor piece inside the injection pump to deteriorate, and pieces of plastic get stuck inside the fittings of the return line which will cause loss of power or stalling.