I have a Onan 4k generator in my 38ft fifth wheel. The generator will run from anywhere from 5 minutes to 30 minutes and shutdown. It is very inconsistent. I am receiveing a trouble code 36 (engine stopped without comand by control). The generator will start right back up after dying. The gen has it's own fuel tank so I checked the fuel lines fuel vent hoses at tank and at fill neck, installed new fuel filter, and ran gen with fuel tank cap off to double check vent system and still same results. I am leaning towards the fuel pump but not sure. any ideas or suggestion would be greatly appreciated.