I have a John deere 4640. Sometimes it works great and then suddenly it works like it’s running out of fuel. Thought something might be at the bottom of the tank but it’s clean, all filters are good which might be a problem thanks guys!
I open the line at the filters — good flow, so I close it. Try to restart it – same problem, I open it again. This time I let it run — it slows down to dripping after twenty seconds! Then I go explore and found the line is blocked on the tee.
Clean filter / sieve (# 13) in the sedimentation tank on the transfer pump ??? I know guys who don’t know they’re there and run them completely plugged in. They will starve the tractor on fuel.
Also, the transfer pump (22) itself can break. Does it work better with a full tank then worsen as the fuel level drops ??? If that’s the case, then the transfer pump could very well be bad. The transfer pump is bolted to the injection pump but is serviced separately. It is simply bolted on and does not affect the removal of the injection pump for servicing. Sometimes you can fix them as well. I will skip it for now.
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