Mep-803a bogging down under load

[Denvercaitland]

Chasing a gremlin. The set has been working fine. New air/fuel filters, read all TMs , fine tuned / adjusted everything I can. 803 is set up for house emergency power or shop use. Using various size shop heater to load. Not consistently, but randomly will bogg down over 40 amps. Never tripped overload, but will rev to ~ 600/800 rpm until bring load down below 40 amps . The only thing I have not replaced are the injectors. Could it be injectors? Photo are when fine under load vs video when randomly boggs down. https://youtube.com/shorts/78lE2_R3xrw?feature=share

 

[DieselAddict]

What Does the generator exhaust look like when this is happening?

Has it been able to drive a full load in the past?

 

[Denvercaitland]

What Does the generator exhaust look like when this is happening?

Has it been able to drive a full load in the past?

See attached video. Running at 40 A and trying to add additional load. Bogging down , a bit of grey/white smoke but that's it. See pic in my original post. Worked at full load no issues but will randomly from one day to the other bog down above 40A.

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[WWRD99]

Chasing a gremlin. The set has been working fine. New air/fuel filters, read all TMs , fine tuned / adjusted everything I can. 803 is set up for house emergency power or shop use. Using various size shop heater to load. Not consistently, but randomly will bogg down over 40 amps. Never tripped overload, but will rev to ~ 600/800 rpm until bring load down below 40 amps . The only thing I have not replaced are the injectors. Could it be injectors? Photo are when fine under load vs video when randomly boggs down. https://youtube.com/shorts/78lE2_R3xrw?feature=share

I looked at the screenshots of the voltage screens...those are nice to have...I assume they're in the house so you can see what's going on...I know you said random times it bogs over 40 amps...the screen shows you're at 240 volts at 13,500 kw at 56 amps...any chance it's hitting overload and lowering output? I think they are rated at 51 amps at 240 but I know they'll do more.

 

[DieselAddict]

will it pull a 4

See attached video. Running at 40 A and trying to add additional load. Bogging down , a bit of grey/white smoke but that's it. See pic in my original post. Worked at full load no issues but will randomly from one day to the other bog down above 40A.

https://youtube.com/shorts/IJwbMSkYA3g?feature=s

See attached video. Running at 40 A and trying to add additional load. Bogging down , a bit of grey/white smoke but that's it. See pic in my original post. Worked at full load no issues but will randomly from one day to the other bog down above 40A.

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Thats interesting. I don't see a dramatic amount of smoke as I would have expected. Are you able to do smaller load increments when you get near 40a? I'm really curious to see the exhaust when you are at about the max load the generator will hold without bogging. You'll need to let it run for 10-15 min at its highest possible load to see if the exhaust has any restrictions.

How many hours have you run this set and what general load conditions does it see?

 

[Denvercaitland]

will it pull a 4



Thats interesting. I don't see a dramatic amount of smoke as I would have expected. Are you able to do smaller load increments when you get near 40a? I'm really curious to see the exhaust when you are at about the max load the generator will hold without bogging. You'll need to let it run for 10-15 min at its highest possible load to see if the exhaust has any restrictions.

How many hours have you run this set and what general load conditions does it see?

Canadian DND surplus set. Put close to 350 hrs on it since I have it ( set is at 1650hrs) What gets me is that it only bog down randomly. I mainly use it to heat the shop in colder weather. I let the set get to temp than start loading ( always try to stay between 80 to 100% to avoid wet stacking) , I can go for a month with that daily routine with no problem, then it will start bogging down over 40A . After a few days Always return to normal full load thus far. - Since you mentioned exhaust restrictions, would a single 90° at the exhaust be possible cause?

 

[DieselAddict]

What is the second pipe for?

 

[Denvercaitland]

What is the second pipe for?

"Artic heather" optional on some set from what I read. Diesel fired pre-Heater, bring the antfreeze temp to 140°.

 

[DieselAddict]

Ah. Ok. I’ve not seen one run that way.

I doubt the exhaust is the problem but worth taking off as a test.

 

[Denvercaitland]

Ah. Ok. I’ve not seen one run that way.

I doubt the exhaust is the problem but worth taking off as a test.

Dieseladdict, as per attached pics and video, using various combination of heater in the shop ( resistive load)I can load from 39A to 46A to 54A without bogging downd. If I try going from 39 to 52 with single load it bog down .

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[DieselAddict]

How long did you run it at 54A?

 

[Denvercaitland]

How long did you run it at 54A?

45 min without problems

 

[Denvercaitland]

45 min without problems

Could it be an injectors issue, that's about the only thing I haven't replaced

 

[DieselAddict]

Yea, seems like you aren't getting any black smoke at all from the video that I can tell.

At this point I would say its either fuel quantity or timing.

 

[Ray70]

So if I'm reading correctly, the machine will take at least 54A by stepping up incrementally without issue, but it's a bit finiky if you dump the load on it too quickly?

 

[Denvercaitland]

So if I'm reading correctly, the machine will take at least 54A by stepping up incrementally without issue, but it's a bit finiky if you dump the load on it too quickly?

Exactly, I'm at a bit of a loss on next step

 

[Ray70]

Since the machine seems to handle a full load when applied in steps, I'm not convinced you have a fuel injector issue.
Sounds more like a governor adjustment issue or maybe sticky metering pump arms causing slow governor response.
Out of curiosity, I would throw the same load on it, let it bog and see if you can overcome the bog by opening up the throttle by hand right at the engine throttle lever to see if it will wind back up to 60 hz.

 

[Guyfang]

So if I'm reading correctly, the machine will take at least 54A by stepping up incrementally without issue, but it's a bit finiky if you dump the load on it too quickly?

Now you can expect a little too much from the set. Dumping a load is not really a good test when you are close to its "Rated" load, anyway. Have you tried to use a IR reading on the output side of the cylinders, to see if the IP's are about at the same place?

 

[Denvercaitland]

Since the machine seems to handle a full load when applied in steps, I'm not convinced you have a fuel injector issue.
Sounds more like a governor adjustment issue or maybe sticky metering pump arms causing slow governor response.
Out of curiosity, I would throw the same load on it, let it bog and see if you can overcome the bog by opening up the throttle by hand right at the engine throttle lever to see if it will wind back up to 60 hz.

Ray70. You were right on , I followed the step you outlined and discovered that the fuel solenoid linkage was binding Slightly on the nut holding it to the governor lever ( wich could explain why randomly the 803 was not taking full load) . Loosened it by a few turn and ran a few test. - thanks to all for the help. Much appreciated. I will post a few video

 

[Denvercaitland]

Governor lever/solenoid linkage

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803 under load

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803 test at 57.5 for 30 min

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