Hi all, we have an Onan QD 7500 in our 2003 Monaco Windsor, and sometimes it has a problem with stalling. It will run for many minutes (sometimes 5, sometimes two hours), and then will hesitate, surge, and die. The code is a 36 (Engine stopped without command from controller). After giving it a good long prime and an extended cranking time, it will start up again and may run for five more minutes, maybe two more hours.
So I'm assuming this is air in the fuel (though I haven't noticed any white smoke). But I've visually inspected the fuel lines and clamps at the ends, and they look good (also confirmed by a reputable shop who had time to take a quick look, but not enough to do a deeper debugging due to my other repairs). Nothing obviously wrong.
Now the strange thing: we just did a rally where we were boondocking, and with a full fuel tank the generator was running great, stalled maybe once in two weeks. When approaching a half tank (another time), it will typically run about 30 minutes (plus or minus) before stalling. Another time when the fuel was approaching a quarter tank, it was stalling every five minutes.
I'm thinking (guessing?) there's something bad with the fuel pickup tube. Maybe cracked or rusted or pinholes? I haven't pulled it out yet, but psyching myself up for it.
So, does my logic make sense? Has anyone had a similar problem or had a fuel pickup tube fail in a similar way? And is the fuel pickup tube easy to remove?
thanks for any advice you can provide before I tackle this,
Jason.