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MEP-003A. Runs rough

Onan

Registered
I have a low hours mep-003a that is only running on a couple of cylinders. The last time I ran it, about three months ago, it ran fine. Now when i try to run it, it runs very rough and does not come up to speed and smokes alot. Do I have an injector pump problem, or perhaps a filter or some thing else. Does running the unit at lower speed have any dangerous effect on the gen elect.system?
Any suggestions would be very much appreciated.
Thanks
Jerry
 

dependable

Registered
Might be old fuel, a little water in fuel, if you have not serviced filters and water separator lately, I'd check that first before wondering about anything else.
 

kwfiggatt

Registered
Running the set at less than 1800 can fry the voltage regulator board - don't do it. I have an mep002a, and it gets started with the throttle set at 1800.

As for your rough running problem, I'd check the injectors. One that is stuck open (or closed) could cause the issues you are talking about. Also check fuel filters and the electric pumps on this set (there are three total - one is used for the external refueling system and two that feed the IP - one is redundant). Also, the pumps have screens in the bottom that probably need cleaned.

In case you haven't found it yet, steel soldiers is a great source of info for the military equipment. steel soldiers

Hope this helps...

Kevin
 

Onan

Registered
Thanks for suggestions for a fix. The fuel and fuel delivery systems are fine. Today as I tried to run the unit, I pushed up on the throttle linkage near the injector pump and the engine appeared to come up to speed. What is that a sign of? I am concerned about running the unit at a reduced speed trying things for fear of harming the electronics.
All sugestions appreciated.
Thanks
 

dependable

Registered
Lube up the linkage and move it some. Get a Killowatt and plug it into convenience outlet and adjust throttle to 60 Hz, if the hertz gauge is still working, great. A lot of times the are not, and Hz reading will help you set correct RPM.

Suggest you get the manuals available free from the site kwfiggatt linked. These are great machines, but they are not plug and play. Most have been sitting for a while and need some basic maintenance.
 

Onan

Registered
Thanks for all suggestions. I believe that I have a broken governor that is not allowing the engine to come up to speed.
I have manuals TM5 6115- 585-12 and TM5-6115-585-34. Servicing the governor looks to be a very involved procedure. Is any one familiar with servicing, repairing this governor. Is there a history with this governor failing? Is there a test I can perform to confirm that the governor is the problem?
Thanks for looking
Thanks
Onan
 

David C

Registered
The governor system on the J/DJ series engines are a robust design and I have not heard of many failures. I would make sure the governor spring did not break. Does the engine run on all 4 cylinders when you manually speed up the genset. What is the frequency meter show when it is running rough?

David C.
 

TomS

Registered
I have both mep 003 and the 002. If all other checks fail, it's likely the injection pump. I have had the same problem with both sets and solved the problem with changing the pump.
 
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