Injection Pump Won't Pump Fuel
My Injection Pump Won't Pump Fuel
***** NOTE This article assumes that you have a good supply of fuel going INTO your pump. If not read http://www.hoyetractor.com/bleed.htm ******
It is very common for injection pumps in tractors that have water in the fuel to stick when setting or when ran out of fuel.
The injection pump has a tiny plunger on each cylinder that is spring loaded. When the cam pushes them up they squirt fuel. When the cam turn more they fall down. When there is water in the fuel or you run out of fuel completely- the cylinders can stick or 'flash' rust slightly & the ultra tight tolerances in the pump get too tight. When the plunger goes up it gets stuck and the spring is not strong enough to push it back down. The cam just spins & either does not make any contact with the plungers or just barely moves them & pumps very little fuel.
A gentle tap of a hammer on the side of the pump mounting flange while cranking the engine will frequently "un stick" the plungers & the pump will start to pump fuel again. More serious cases require the pump to be removed & rebuilt.
*** NOTE: Do NOT ATTEMPT to remove your injection pump without unhooking the internal governor linkage FIRST !!!! This will damage the fragile governor linkages & springs and will be very difficult to repair!! You may need to consult a service manual before removing the pump.**