MEP-005 engine surges, won't stay at consistent throttle

[asajay]

After removing the glass-ball fitting and replacing it with a straight through non-restricted fitting, I've been able to get my MEP-005 to start and run. But now I can't get it to stay at a consistent rpm. The fuel appears to be clean. I've taken the top of the injector pump (IP) off and it appears pretty clean, though there could be junk floating around I'm not aware of.

New fuel filters and the separator has been cleaned.

The engine starts and I can adjust it to 60Hz, but then it starts to "hunt."

It will slowly drop rpm to nearly 53Hz and then suddenly jump back to 61Hz or so, fall back to about 60Hz, then slowly start dropping to about 53Hz, jump back up, rinse and repeat. The throttle cable is in good shape and not moving.

My guess is there is junk going through the injectors or there is some kind of a governor on the engine. I'm entirely new to diesel engines and how it all works on this MEP-005.

The Injection Pump is a Stanadyne DBMFC 633 1LK
The engine is a White model number D298ER

It "hunts" regardless of a load being attached or not.

What kind of things should I look for, outside of the IP needing to be rebuilt? Are there other things that could cause this? Blocked injectors, lines, etc?

Thank you,
Asa Jay

 

[asajay]

I just spoke with a local diesel pump repair house. They say this could be due to a governor going bad in the pump or air getting into the lines. Based on the age of the generator and the look of some of the fuel lines, I'm going to go with replacing all the rubber hoses between the day-tank and the IP first, as well as making sure all other pipe fittings are sealed and flare fittings are tight. I hadn't thought of air being a problem.

The shop quoted me $500 parts and labor for a typical rebuild of this specific pump. If it needs any special parts replaced, it could run a little more. Based on what I've seen, this sounds like a pretty good price.

Hopefully it warms up a little more to give me more incentive to go out and work on it.
Asa Jay

 

[Guyfang]

This is a fuel/air problem. Check the electric fuel pumps to be sure they are clean, and that then are pumping enough fuel at the right pressure. then start looking for fuel leakage/seeping, on the fuel system. If I remember correctly, there should be an adjustment knob on the injector pump. Droop adjustment I think. Maybe someone fooled with it? In any case, sounds like the system is getting air. Oh, the glass ball fitting is to keep your fuel system primed. The fuel will run back towards the filters and then your set is hard to start or will not start.

Guyfang

 

[asajay]

Guyfang,
Thank you for the advice. Removing the glass ball has not affected starting, even in cold weather. I use the Run and Battle Short switches to prime the system and it starts right up.

I will add the electric fuel pumps to the list of things to look at, clean and/or replace.

The knob on the back of the pump -has- been moved, I know that. After I inspect all the other items for air leakage, I will need to research the proper way to adjust that setting. I've seen some other posts that talk about that knob, so perhaps the answer is here somewhere.

Asa Jay

 

[Guyfang]

Mep-005

Guyfang,
Thank you for the advice. Removing the glass ball has not affected starting, even in cold weather. I use the Run and Battle Short switches to prime the system and it starts right up.

I will add the electric fuel pumps to the list of things to look at, clean and/or replace.

The knob on the back of the pump -has- been moved, I know that. After I inspect all the other items for air leakage, I will need to research the proper way to adjust that setting. I've seen some other posts that talk about that knob, so perhaps the answer is here somewhere.

Asa Jay

Jay, do you have access to the TM's? Its been a while, I have been out of the army almost 23 years, but I seem to remember that the TM explained how to go about adjusting the pumps.

Guyfang