MEP-831a Troubleshooting

[Cord]

Is the spherical nut on the bottom of the rod all the way down on the last thread?

I'll have to check tonight. In the video above you can see the amount that is above the lever. Not sure if that is helpful or not. When we adjusted the rod length, I screwed the rod out from the spherical end.

 

[Cord]

That trailer set up looks great!

Thanks! It was a fun little project. If I were to do it again, I'd set the tires outside of the unit. We started with this design but changed it when we realized the trailer would be wider than the atv. Not the best for running through the woods. What we didn't realize was that the fuel would slosh and make the trailer unstable. To lower the center of gravity I welded a 120lb steel bar to the axle and this has helped. If I were to do this again I'd go with the wider stance and hope it doesn't get bounced off a tree.

 

[cdre]

Might consider replacing with a baffled tank to reduce free surface effect.

 

[Cord]

Is the spherical nut on the bottom of the rod all the way down on the last thread?

There are no threads showing.

 

[Dewie38]

Down to the last thread no further?
The bottom of the spherical nut has to be on the last thread at the end of the linkage rod.

 

[Cord]

I couldn't see any threads. Right now I adjusted the rod so it was slightly longer. If I raised the spherical nut, then wouldn't I need to readjust the rod length by the same amount? Seems like it's not really changing anything.

 

[Cord]

bump

 

[cdre]

If you have two sets, one has output one doesn't, what I would do is remove the actuator from one with no output and install in the one that is running bad.
See if that helps get at least one up and running good, then mess with the other issues on the other set.
One connector and two bolts and the actuator is removed.
If that works then you at least will know the actuator may be out of adjustment or bad.
What I don't like what I see is the actuator slams all the way open when the set is started, shouldn't do that.
Also when the set is started, the rod shouldn't come out of the seat either. The black spherical nut on the rod should always be in the seat.
The one that has no output because the PMA isn't putting out enough voltage, may be because the speed is to low.

So I disconnected the inputs to the actuator and the engine settled out to a nice idle - no issues tied to the engine or oil level. Swapped out an actuator from a known good unit and still the same violent surges - not an issue with the actuator. So, has to be a controller problem or something upstream of there. I read through the controller adjustment procedures. Could the "stability" adjustment or any other dial on the controller be the culprit? I'll go through the full adjustment process tomorrow.

 

[Cord]

I suspect it's a stability issue. It helps to have a second person to help with the adjustment procedure. Have a pen and pad of paper handy. After making adjustments, go back over the numbers again because subsequent adjustments will throw the initial values off. Be careful to not skip any steps or you'll have to start over.

Now, can anybody help with my shut down issue?

 

[R Racing]

My rod on mine had come loose on the spherical end and shortened by about 5/16 . I measured the other unit I have and re adjusted it and fixed my shut down issue.. I didn't have to make any adjustments to the governor side.

 

[Cord]

What's the length so I can check mine?

 

[R Racing]

I'm just getting back from a funeral . I'll get a measurement for you and report back.

 

[cdre]

So I'm continuing to try to find the source of my surging speed. Yesterday I disconnected the signal to the actuator and the engine ran beautifully - so the issue is upstream of there. Then I swapped a known good actuator (stable movement) with the one that is surging. The known good actuator arm did the same thing, so the problem is further upstream. (BTW, both arms showed 10 ohms of resistance - in spec). So I got brave and starting playing with controller dials. First I checked to ensure the controller was getting a steady 24v when in "run." Confirmed. Then I connected to the A and B terminals on the controller. With the engine running, I'm getting fluctuating voltage readings but between 160 and 200 which make sense based on the engine speed. Original paint marks are on the linkage hardware, so I didn't tinker with that. Realizing stability is achieved by turning the knob clockwise until unstable then back a little, I turned the stability knob fully counter clockwise which should presumably stabilize things. No change. Then gain fully counter clockwise. No change. Then I connected the multimeter to the actuator terminals. My multimeter is too slow to really show what's going on, but you can see that it's cycling between 0v and 24v. Video below showing the signal being sent to the actuator (alligator clips slipped off in the video which is why it initially showed 0).

Any thoughts on what the issue could be beyond what I've thus far troubleshot?

https://youtu.be/9clqDLwYnrQ

 

[R Racing]

What's the length so I can check mine?

Ok here is a picture of the measurement. I hope this helps you .

 

[cdre]

Governor Controller - Does the governor controller rely on "PMA Voltage" coming from the generator to do it's job? Trying to do some troubleshooting on another genset and realized the "battery +" is only activated when the start switch is in "start" - based on the K12 relay (Fault Lock Out) giving it power only when it is "open." I observed that the actuator goes to "open throttle" shortly after "start" presumably to help the engine start. After "start" is released, the relay closes (thereby opening the circuit that was giving the governor control it's 24v).

So my assumption is that the battery 24v is only used as a signal that the actuator should open the throttle, then disregarded when running and that the PMA voltage is used as a power source by the governor controller thereafter.

Is this true?

 

[cdre]

The one that has no output because the PMA isn't putting out enough voltage, may be because the speed is to low.

Just realized this probably confirms my assumption. When I manually rev the engine, I can get the voltage I expect to see. Likely need to make some mechanical adjustments.

 

[cdre]

Mechanical adjustments are going to take a while and I had limited time this morning so I thought I would try a couple of things on my "surger." Realized last night that at least half of the relays that came with my 831's are 120vAC driven rather than the 24vDC called for in the techman. I replaced the suspected relays in my surging genset this morning. Fired it up and same result - uncontrolled surging. I prevented the actuator from returning all the way to the magnet to see if the magnet was pulling it in but not the case - still surged from my stopping point to full throttle. Then I realize the indicator on K12 wasnt lit. Also heard a buzzing sound from K15 - felt it buzzing as well. I'm going to pour over the diagrams to try to see why K15 would have an inconsistent circuit and why K12 isn't being energized (closed). Odd thing is that it looks like K12 is getting consistent power and K15 is showing extremely low (or likely short bursts) of + current.

Video of this morning's experiment below...

https://youtu.be/6uTuYUCtqgM

 

[cdre]

Looking through the wiring diagram I realized K15 should indeed be a 120vAC relay as it's actuation feed is AC. The techman doesn't differentiate on the parts listing - just shows the same DC relay for all 3 slots. Switched out to the appropriate relay and had the same result except that K15 was well lit and K12 went dark as soon as the genset fired.

 

[R Racing]

My k12 has a red led on when it runs ??

 

[cdre]

I don't know if red or green makes a difference. I think they just have the one indicator to light up when the relay "closes."