MEP-003a will not pull load

[Isaac-1]

I have a MEP-003a that I bought about 8 months ago that I have been slowly fixing up, Anyway today I finally got around to doing a formal load test on it and the engine starts to stall out and rpms drop off at around 4.5 - 5KWs manually throttle addition will not pick up rpms, and addition of an extra 500 watts causes rpms to drop off drasticly. By comparison my MEP-002a which I also tested today will pull a over 7.5KW although it is not sounding happy at that point.

History of possibly relevant topics, this generator has always been hard to start, starts off on 2 cylinders, then the other two start firing within a few seconds (I changed the diesel injectors with tested working ones on the two slow to fire cylinders, it helped but did not solve the problem). It smokes mostly from the slow to start cylinders for 30-60 seconds, then mostly clears up, with only a very faint wisp of smoke from what I suspect is one of those two cylinders. I was hopeful that putting a load on it would help clear this up, but after 30 minutes at 4.5 KW today I saw no change at all, adding another 500 - 1,000 watts would cause rpms to drop off, etc.


I have not yet done a compression check (need a glow plug to compression gauge adapter), and I have not yet checked the valves, maybe next weekend will work out for that.

Is there anything else you can think of that I should check?

Ike

p.s. just thought I should check head temp with IR gun, did not have it with me today, but will try tomorrow if I get a bit of free time

 

[dangier]

Isaac-I had a 002 do that (start to stall around 70-80% load). Did the Jerry tune on the injectors and little change. Turned out it had a worn IP. Replaced with new from Gimpy and it still runs great....
Is the timing ok? You still should check the valve adjustment though.
David

 

[dependable]

Ditto on checking the timing. Someone may have put the wrong button in it or removed/added shims.

 

[cuad4u]

Ditto on the defective IP. My 003A did EXACTLY the same thing. Bought a rebuilt IP from Delks and the 003A will load test 12,500 watts all day. RPM's only start to drop off when I approach 15,000 watts. I do not recommend running it that hard, but with the rebuilt IP, it will do it.

 

[Keith_J]

When you say manual throttle, do you mean at the injector pump? Or at the governor's adjustment (knob at the control panel)? This could be a gummed up injector pump throttle linkage. This is on the side of the injector pump. When disconnected from the governor linkage, it should move freely. Since diesel is on one side (at priming pump pressure) and open to air on the other, it can gum up. Clearances are tiny, there is no other seal.

The governor force is also tiny. Try a little Berryman B12 carb cleaner on it if stuck or not freely moving. Do not let this run through the injector pump.

 

[Isaac-1]

Thanks, for now I only tried to adjust engine speed at the knob, will check linkage, but I suspect with the way this sounds that the injection pump will be coming off soon. I bought an injector tester off ebay and tested / replaced these myself, but did consult Jerry on the process.

Ike

p.s. I may see about swapping the good working injection pump from my MEP-002a and see if that fixes things, may be the quickest option. I also have an M-50 injection pump on a potentially scrap civilian Onan DJB that I paid $100 for (missing control box, etc.).

 

[Jimc]

mine used to start smoking at about 80% and die at 90. i let jerry do the injectors and it will run all day now and barely smoke at 130. thats with one cyl with very slightly lower compression. it takes a min to heat up and for that one to clear

 

[dangier]

After having the injectors done on my running 003, it will put out 16,800 watts @240 volts (131% indicated load), so far up to an hour with just light fuel smoke. Have not pushed beyond that as my house does not pull that much. Once set up right, they can do it very well. I also might have compression issues as I am getting blue (oil) smoke on start up for a minute. Clears up and runs clean after that. Wondering about maybe sticking rings. Not always same bank of cylinders.
David

 

[Isaac-1]

Considering I am getting to only about 30-40% load before the engine bogs down, and that I have changed the injectors out for working used ones on the 2 cylinders that were smoking and slow to fire off. (pop off pressure is right, spray pattern may be less than perfect), I can't see that the other two would likely be bad enough to keep load that low, although I guess it is possible that there are multiple factors. If this were getting 70-80% that might be a different matter. So this leaves me thinking it is likely something in the injection pump. I guess it could possibly valves or compression, but I would think I would see more smoke if it were. It just seems to have a starved for fuel feel to it.

 

[dangier]

Isaac

I may see about swapping the good working injection pump from my MEP-002a and see if that fixes things, may be the quickest option.

Do the flow timing method with the existing pump. That would discount timing for now. If you swap the 002 pump I would flow test that one too before trying to start in on the 003. You may have to switch timing buttons around. Be sure and record what number button came from the 002 so you can put it back. Don't know about you, but I need a lighted magnifying glass to see the little numbers on the side of the button. I tried switching IP's around on the first couple of 002's I had and I lost track of what went where. Took awhile to figure things out to make them run.

David

p.s. Have you flushed all of the supply and return lines to and from the injectors?

 

[dangier]

Isaac,
Making any headway?
David

 

[Isaac-1]

Nothing yet, came down with some 24 hour bug (well more like 12 hour) this week, don't know what it was, but it came on fast and had some punch, 103+ degree fever, chills, etc. I have spent the last 2 days just trying to getting some of my energy back. I think I have slept about 36 of the last 48 hours. With luck I plan to get back to this project this weekend if nothing else comes up.

 

[dangier]

It's making the rounds in our family for the past 3 weeks. Grandchildren have had it twice!
David

 

[Isaac-1]

I traced at least most of the problem to the compressible linkage in governor linkage, it should be 5.5 inches and had unscrewed out to about 6.25 inches. I am now pulling just over 10KW before it bogs down, I think I need to replace the ball joints on the linkage as there is a lot of play in them.

Ike

 

[dangier]

You should be able to get upwards of 16,000 watts. Is this the one with the hard starting?
David

 

[Isaac-1]

Yes, it is, so I am not sure it is all governor issue or not, but I have now more than doubled the load it will pull, so that is progress. I was running out of daylight at that point so decided to call it a day. I did not get as much time over the weekend to work on it as I would have liked, other projects kept requiring my attention.

Ike