John Deere 300B Injection Pump Question.

Axl2011 · Nov 4, 2019

The tractor recently refuses to run. It started off staying running for only about a minute and cant throttle or anything. Then it would stall out. Now it will not run at all. Changed fuel filter and fuel pump. Cleaned out the injectors. Next thing I can think of would be the Injection Pump? Does this seem like the amount of fuel it should be spraying to injectors or should it be heavier?

John Deere 300B Injection Pump Spray - YouTube

thepumpguysc · Nov 4, 2019

That's plenty of fuel..
If it has a RoosaMaster/Stanadyne inj. pump on it.. remove the return line & ALL the fittings all the way down to the alum. cover..
NOW start it & see if it runs.. betcha it does.
The fuel WILL flow out of the hole & that's what u want.. just be prepared.. get a pan if its gonna be a problem.

Axl2011 · Nov 4, 2019

thepumpguysc said:
That's plenty of fuel..
If it has a RoosaMaster/Stanadyne inj. pump on it.. remove the return line & ALL the fittings all the way down to the alum. cover..
NOW start it & see if it runs.. betcha it does.
The fuel WILL flow out of the hole & that's what u want.. just be prepared.. get a pan if its gonna be a problem.

This is my pump if that helps any. After I remove the lines and let's say that is it (I Hope!) What next? Reconnect them after it drains and it should be good to go?

thepumpguysc · Nov 5, 2019

Its either 1 of 2 things..
The check ball connector is clogged from dirt going thru the pump..
OR.. the flex ring inside the pump has broken up & the "bits" are clogging the connector..
& that requires an o/h to be repaired..
IF it stays running.. CLEAN OUT the check ball connector & put all the pieces back on>> 1 # A TIME..
IF it stays running w/ the connector back on the pump.. put the return line back on..
IF the engine dies when the ret. line is screwed on, u have a blockage in the line going back to the tank..
Let us know..
U can contact me direct if u like.. click on my screen name & that'll get u to my contact info.