I have a 2008 Holiday Rambler Admiral Class A with an Onan Marquis Gold 5500 gasoline generator. When running for about five minutes it will start to choke and then shut off. The gas tank is full. This happens whether I have a load on it or not. Where do you suggest I look to troubleshoot? The manual indicates the fault code is 36, which suggests the fuel pickup might be higher than the vehicle engine pickup, but again the tank is full. I’ve recently serviced the air cleaner and changed the oil. Any suggestions?
Bill Thom l Via email
It’s likely the genset’s fuel pump, but do some checking first. Remove the gas tank cap and listen for a suction (whoosh) sound that might indicate a partial vacuum is forming as fuel is used. Check the fuel filter, too. I’ve heard that Onan had a problem with its supplier using the wrong rubber seals in the pump and as they heat up the rubber swells and stops the pump. You can try running the genset with an external fuel supply held above the level of the carburetor (with the line attached directly to the carburetor). If it runs fine then, get a new pump.
— Ken Freund