MEP-002a poor performance under load test

[heritageequipment]

Hello,
We have a few MEP-002s that bog down with only 2-4kw when using the load bank but run perfectly fine otherwise. I have tested some that went up to 7500w. The manuals simply says to check the air filter if they have low power. Is there a thread or check list to know where to start with low power output? Actually one of them has a brand new crate engine (well military rebuild) that we put on the unit and it wont put out more than 2k without bogging down.

Rebuilt engine unit
-Governor is very tricky to adjust on this one, It either overspeeds the one direction or bogs the other, I cant get it to hunt.
-bogs at 2kw
-super clean...well it just came out of a crate!


1500 hour unit
- Governor adjustment works well, it hunts one direction and droops the other, and I think I found a sweet spot in between
- bogs down at 3-4kw
-once it starts bogging you can push on the linkage to get it to speed back up

Both units start right up with and dont smoke at all

What is the flow chart of diagnosing low power units? What order should I do the following things, or what else do I need to add to this list?

1. Check compression
2. have injectors pressure set
3. check fuel pressure to injection pump with gauge
4 check valve lash
5. Check injection pump timing
6. injection pump output pressure
7. ?

The injection pump timing procedure looks like voodoo magic to me....so I would like to save that for a last resort, lol

 

[jamawieb]

More than likely just the injectors. Storeman has checked and rebuilt all of mine over the years. Over time the spring inside the injector gets weaker and it needs to be readjusted. But the only way to test them is to build a pop tester
99% of the units that couldn't hold 8kw was because of the injectors. Only 3 out of 150 I've sold was due to injection pump timing.

 

[Guyfang]

Hello,
We have a few MEP-002s that bog down with only 2-4kw when using the load bank but run perfectly fine otherwise. I have tested some that went up to 7500w. The manuals simply says to check the air filter if they have low power. Is there a thread or check list to know where to start with low power output? Actually one of them has a brand new crate engine (well military rebuild) that we put on the unit and it wont put out more than 2k without bogging down.

Rebuilt engine unit
-Governor is very tricky to adjust on this one, It either overspeeds the one direction or bogs the other, I cant get it to hunt.
-bogs at 2kw
-super clean...well it just came out of a crate!


1500 hour unit
- Governor adjustment works well, it hunts one direction and droops the other, and I think I found a sweet spot in between
- bogs down at 3-4kw
-once it starts bogging you can push on the linkage to get it to speed back up

Both units start right up with and dont smoke at all

What is the flow chart of diagnosing low power units? What order should I do the following things, or what else do I need to add to this list?

1. Check compression
2. have injectors pressure set
3. check fuel pressure to injection pump with gauge
4 check valve lash
5. Check injection pump timing
6. injection pump output pressure
7. ?

The injection pump timing procedure looks like voodoo magic to me....so I would like to save that for a last resort, lol

Just a few comments. I am on my way out the door to a bike rally, so cant take to long.

1. Have these sets ever run right? Did you get them in this condition?
2. Keep in mind, if your electric fuel pumps dont work right, the gen set will bog down. If the check valve is not operating, same problem. Sometimes, when the second electric fuel pump doesn't work right, or stops working, the set will run, but the first electric pump has a hard time pushing fuel through the second pump.
3. A quick and dirty way to see if compression is a problem is to open the oil filler cap. Got back pressure? Is the oil thin? Smell like diesel?
4. Timing is a problem rarely seen, with these symptoms. And the procedure works well. But it's about the last on the list to check.
5. Jamawieb is right. Sounds like the injectors should be looked at.
6. Have the sets been standing a long time? Lacquer buildup can be a problem in the fuel system.

Just a few quick ideas. Now, off like a dirty shirt! Everyone stay safe, and have a great weekend!

 

[heritageequipment]

We sent out the injectors to have them calibrated by Storeman. After reinstalling the injectors the one set runs exactly the same and bogs down to early. I will look into the fuel pumps now. I guess the best way to check them is to put a pressure gauge after the pumps? What pressure is ideal? These sets have no problem running on one pump, correct?

 

[DieselAddict]

Can you shoot some video of it running then bogging down? We need to see how you are measuring the load and the condition of the exhaust stream.

This is what one that is wetstacked looks like when you try to load it. https://www.youtube.com/watch?v=j9cI1l77fbg

After running it and cleaning everything up this one would accept 6.5kw without complaints.

I'm a fan of doing leakdown tests and compression tests on a unit that won't make power and doesn't show signs of wetstacking.

When you apply load, what are your increments? Can you load it just under what it will accept without bogging and see if it will do that for some period of time?

I am wondering if you are not getting it hot enough to know if you have an exhaust full of crud.

 

[Bmxenbrett]

Did you adjust the fuel at the injection pump? That stud and nut that holds them down also alows you to turn the IP in the block when loose. When you turn it your basicly allowing the rack to slighly close off the fuel output. Im not sure of the proper way to adjust them but im sure its in the TM or guy can tell you.

 

[jamawieb]

Did you adjust the fuel at the injection pump? That stud and nut that holds them down also alows you to turn the IP in the block when loose. When you turn it your basicly allowing the rack to slighly close off the fuel output. Im not sure of the proper way to adjust them but im sure its in the TM or guy can tell you.

You're thinking of the 802a he has a 002a. No adjustment on the 002a's single pump.

 

[jamawieb]

Check the valves for proper clearance.

 

[Triple Jim]

It could have the wrong timing button.

 

[Bmxenbrett]

Yes i am thinking of the wrong gen. Sorry.

 

[Ray70]

Try checking the throttle linkage bar going to the side of the IP. I have an 003A that the military painted and the thick layer of paint has frozen up the sliding section of the linkage and it would bog at around 5KW ( 50% rated load ) after freeing up the linkage it will now pull 14KW all day long.... sounds like your 002A is petering out at about 50% load too...

 

[Guyfang]

Ray is talking about the throttle linkage universal joints. On both ends of the linkage are two "ball joint" adapters. Very common problem, carc paint covers them and they no longer perform correctly.