D950 Injector Pump Question

[Kubit]

My D950 engine injector pump mounting block has on the rear facing side a small adjusting screw & lock nut which adjusts a small internal coil spring which I think pushes against the pump rack. Wondering what its purpose is & how to determine proper adjustment--it is not shown in any of my manuals

Pump was leaking at top outlets—had it rebuilt at Oregon Injector & now reinstalling, the pump is a Denso unit.

Thanks,
John

 

[kubotafreak]

One on the timing cover side is the high fuel spring adjuster. The one on the back side is the idle fuel spring adjuster. The rpm is usually external on the speed plate, as limit screws. The fuel adjusting screws should have a single or double lock nut with sealing washers. They crimp the cover over to inhibit tampering.

 

[Kubit]

One on the timing cover side is the high fuel spring adjuster. The one on the back side is the idle fuel spring adjuster. The rpm is usually external on the speed plate, as limit screws. The fuel adjusting screws should have a single or double lock nut with sealing washers. They crimp the cover over to inhibit tampering.

Thanks for your reply kubotafreak, so this would be the idle fuel spring adjuster that you note. When removed the end looks like a blunted gas carb high idle adjusting screw, except that the coil spring is recessed into the pump block. I didn't notice it when I pulled the pump & only saw it when beginning to install the repaired pump. Amazing that spring didn't fall off & lay hidden beneath the cam shaft when I pulled the pump. I wouldn't have looked for it since it is not shown on any D950 parts manual that I have access to--I removed it & reinstalled from the outside of the block after the pump was bolted down.

I'll do a "low tech" final adjustment: (4) screw threads showing with adjusting slot vertical.

John

 

[kubotafreak]

Ya, shouldn't be too bad to get it back. I rarely ever adjust the off idle fuel screw. My unscientific approach to the high, is to put machine at full load, adjust till it starts to have unburned fuel, and back it off 1/4-1/2 turn. Once you get to the ideal spot the adjustment is within 3/4 of a turn.

The manual injection diesels are fairly simple.

 

[Kubit]

Ya, shouldn't be too bad to get it back. I rarely ever adjust the off idle fuel screw. My unscientific approach to the high, is to put machine at full load, adjust till it starts to have unburned fuel, and back it off 1/4-1/2 turn. Once you get to the ideal spot the adjustment is within 3/4 of a turn.

The manual injection diesels are fairly simple.

Thanks again--this unit is in a marine Genset so I need to be real careful about that high end stuff