Kohler Genset Fault Code UF

Hi there, We have a new to us 10yr Mainship with a Kohler 8EOZD diesel generator. Over the past two weekends while on the hook with the Genset on and two of three AC units on, it just quit. A look on the controller showed a blinking fault code of UF - Under Frequency.

I restarted and used one AC (and the other things like battery charger and fridge) and it quit after about 45 mins. Down below I go, see the blinking UF code, reset the controller and fired it up up again. While running with no AC it runs ok, but as soon as I load it with one AC the speed of the engine decreases and it looses frequency and shut's down. This happened today and the time it ran fine before stopping got less and less. Finally, after reset with a differenc AC unit on, it only ran for a few minutes.

The clear fuel filter looks fine. There is plenty of water coming out of the exhaust. It draws fuel from the same tank as my port engine which runs fine. Tanks are at 5/8th full.

Any ideas?

Thanks much,

JimL

Had the same problem had the wire to the fuel pump loose that fixed that problem. We did get rid of it for having lots of problems

uf is under frequency shutdown. you are ether overloaded or the unit is short on hp to make the rated kw.

Check that the elec fuel pump is working and change the fuel filters. Sounds like it is starving of fuel.

I ran it this evening with no load and it ran fine. I loaded with the routine items: fridge, battery charger etc ok,

When I added a load, with two AC's it quit. It was fine a month ago. I'll start with the fuel filter and see what happens.

Thanks for the advice.

JimL

Hi,
Having the same UF error code. How was this resolved?
Thanks -

I had the same issue on mine (same code) that was fixed after I changed both filters.
Good luck,