Onan genset stops running--------Fixed

soxbrat wrote:
Here's what solved my problem, yesterday. Started the genset. it ran for 3 minutes before surging and dying. It wouldn't restart. Amp draw was a consistent .78 amps right up to engine shutdown. I happened to have another, used, pump that I installed. This pump showed .80 amp draw. Generator started, powered up and ran for an hour with A/C running. I'm calling this problem solved. A new pump from Cummins was about $120 so it's not an inexpensive fix, but it was simple to get to and only about a 5 minute swap so you shouldn't have to pay to have it replaced.

I hope you found the problem, but I don't know if I'd make the same conclusion about the fuel pump being the issue with the currents you measured. The difference between 0.78 Amps and 0.80 Amps is only about 2.5%. That's within the range of accuracy on DC current scales of many DMMs and Multimeters, so depending upon the meter you're using, it might not be an accurate indicator. Plus, knowing NOTHING about the electrical specs for the fuel pump, that variation may well be within the operating specs as oftentimes the ranges seem to be around + 5 % or even + 10 %.

Now, the fact that putting a different fuel pump in kept the generator running...then that is obviously a good sign. :) Just not so sure you can make that determination from the current measurements.

I hope your diagnosis is correct. Please keep us posted on longterm operation.

~Rick