mf 750 fuel problems

[Anonymous-0]

can anyone tell me why my massey 750 loses its fuel to the injection pump after it sits a few days. it starts fine if run everyday.

 

[Anonymous-0]

if it has a mech. lift pump like a 510 the check valves are leaking by, had a 510 that did that, changed pump and cured problem

 

[the tractor vet]

Also drop the sediment bowl and clean the bottom of the tank and the inlet screen as i have found many times that bean dust really builds up in the bottom of the tank and also check the vent on the cap as it may not be allowing enough venting and causing a vacume and this may be pulling the fuel back

 

[Anonymous-0]

On my Massy 550 combine there was a check valve screwed on below the mechanical fuel pump that supplied the injection pump. I would certainly think that if the check valve was "stuck" open allowing the fuel to drain to the tank fuel level that starting would be slow. I had a wad of soybean chaff in that check valve once on the upper side of the ball in the valve. The combine would run fine for a period of time. Then the wad of chaff would slowly rise and plug the small hole at the upper end of the check valve. Maybe something like chaff is holding the ball from seating 100%. Good luck.

 

[STUDIEDIESEL63]

Ours was getting air because of bad o-ring seal on the filter bolts,did the same thing you are describing.

 

[bofootball57]

(quoted from post at 18:25:00 08/10/09) can anyone tell me why my Massey 750 loses its fuel to the injection pump after it sits a few days. it starts fine if run everyday.

All Massey 750s have this problem, basically any older Massey diesel combine. The Massey fuel system is bad. Best way i have found to deal with this issue is go to your local auto zone, Riley parts, and get a 30-40$ diesel pump(4lbs of psi). Clean your bowl, then add the pump after the bowl so it pushes fuel up to your lift pump(located on the backside of the block-lever on it to push fuel to filters and injection pump) wire up a switch in your cab and hook up to battery. Just turn on pump before you start and leave running while combine is running.

Note: You have to bleed the fuel system after installing pump. One man crack the lines before and after filters and then before injection pump, another to work lever on lift pump on back side of block. Make sure your new diesel pump is on also. After bleed, someone crank engine over while some on still works lever on lift pump.

Sounds like a lot but it is not bad at all, I have done this on several 750s, and a few 540s i would not go into a field with out one