MEP-805a won't stay running after grounding out + battery cable on starter.

[bareaneye]

I sold a generator to a customer of mine that ran perfectly, even after doing a 2 hr load test. The batteries were moved outside of the enclosure and new longer battery cables were purchased.
I had the customer install them and he installed the bolt lug crimped end at the starter backwards and it was touching the starter housing. When he hooked up the positive battery clamp on the battery, it of course arc'd. He went back and discovered the cause of the arc and switched the clamp at the stud so it wasn't touching the starter housing.

We started the generator and it ran as it should. I should mention this generator was installed in a trailer for use as the power source for a spray foam insulation rig.
He took the rig back to Northern Idaho and the next day it started giving the overspeed code and the hertz was all over the board and uncontrollable. Voltage was low as well.
He took it to a generator repair shop and they begrudgingly worked on it.

They managed to adjust the linear actuator/ gov and seemed to have got it going with proper volts and hertz. Customer took generator home and then the machine started again with the overspeed code and hertz out of control. It would run for a bit around 30 seconds and then trigger a code and turn off. Now it runs a few mins before it shuts off.

I have a feeling something fried when the battery cable on the positive side was connected and arc'd.

Any ideas where I should start? My gut tells me the voltage regulator. Anybody in the St. Maries, ID area that could help with this?

Thanks! Craig

 

[bareaneye]

So I arrived yesterday at the customers shop and started the unit. It ran perfectly for a few mins and then started to increase in speed and the hertz went wild. I switched out the linear actuator/ speed control and then ran it for a bit. Voltage held steady as well as the hertz. I am going to run it for a long period of time today and see if it holds.

 

[bareaneye]

Ok, we seem to have it narrowed down to the injector pump. Adjusted the linkage several times and it ran well until it didn't. I called the shop who rebuilt the injector pump a few years back and before I could finish my sentence, he told me to take off the fuel filter, dump it and fill it with transmission fluid. Then pour the rest in the fuel tank. We ran it for several hours with good success but had a few times it dropped in RPM's. Stopped and restarted and it ran flawless. Finally it did it a couple of more times and we just blipped the linkage and it settled back to where it's supposed to be.

I think it just from non use over the years. We are going to continue to run it and apply load to it tomorrow, In addition, the injection shop suggested we add a small bottle of 2 cycle oil to every other tank of fuel for lubricity. Hopefully this is the cause of the speed variation.

 

[cstumpf750]

I recommend Opti-Lube XPD for fuel additive. But here’s some info and research into diesel fuel additives

 

[bareaneye]

It seems as though the transmission fluid may have solved the problem. Even though I had used a fuel additive, it was only run once a month without load.
This coming week will either put it to bed or more investigation will be needed.