MEP-803A Injection Pump sticking

[Guyfang]

Have you downloaded the TM's yet? Everything you ever wanted to know about your gen set, in in them.

 

[Ray70]

Good advice Guyfang. You need the TM for reference, pictures and descriptions are invaluable.
The fuel rack is the long stamped steel bar that sits inside the engine block, just under the metering pumps.
It connects the governor and fuel stop lever to the arms on the metering pumps.
It is spring loaded and has a notch under each pump to accept the pin on the end of each pump's lever arm. this is what controls fuel volume per stroke.
Because it is spring loaded and not directly fixed to the exterior throttle lever, ( in the "On" position ) if one of the pump's lever arms is frozen, the throttle and fuel shut-off levers on the outside of the engine will still appear to be moving correctly but the fuel rack inside the motor can be stuck in the off position.
It is only engaged by springs that push the fuel rack "ON" and a mechanical lever arm that pulls the rack back to "off" when the solenoid is disengaged.
Grab the TM here on this site and locate the pictures and you will then understand completely.

 

[HyaliteHeavy]

I have checked the three TMs that I have downloaded from GMG but I was unable to find any reference to the "fuel rack". With your explanation Ray70, I know understand the apparatus that people have been referring to. I wasn't able to get beyond the "3-12 BLEEDING/PRIMING FUEL SYSTEM" because I didn't find any further indication of steps to take if I did not have fuel pumping from the delivery valve holder. I've now been guided to the observation that my injector pumps are not pumping and I've started the process of cleaning as described by jamawieb, Ray70, and DieselAddict. Thanks, boys. I'll be in touch.

 

[Daybreak]

Howdy,

Start off in this thread. MEP-802A MEP-803A Filters and Parts

The 2nd post has quick links.
The 3rd post has quick links to the TM's here

 

[majoday]

The pumps are very simplistic and I've had several apart to clean them. Try carb cleaner as mentioned above and then spray with wd40. If they continue to be hard to move then they are not put back together correctly. Take it back apart and reassemble.
How do you know the piston is not going to the bottom of the stroke? The large spring on the bottom of the pump holds the piston down and when that spring is comprised by the cam is when it sends the piston upwards, which pressurizes the fuel and sends it to the injectors.

How do you go about taking injection pumps apart. I pulled #1, very rusty body, but the part in the block is pristine.
I sprayed carb cleaner on it. I removed a keeper spring, not the bottom spring, to have a look. The fit is very good, if the piston is that narrow part with the machined cuts in the top. Any suggestions would be welcome. The gen set was contaminated by really bad fuel. I have cleaned the lines. I have cleaned the body on a wire wheel.