RV Repair: Onan generator wont start, coach tank, oil pressure sending unit

Question
The Onan generator of my RV cranks, starts then stops after 10 seconds whether I hold the button or not. I changed the oil, checked the batteries and cleaned the posts. It still doesn't work. I have a code 32 and did everything written in the troubleshooting. I saw something here about varnishing fuel. Could this be the case?

Answer
Hi Eric:
Most of the time when I have Onans that come to my shop and do not start it has been fuel.You should make sure first that you have spark in the ignition circuit. I usually pull off a spark plug lead and use a spare plug, plug in the lead, hold the plug body to ground and crank. If you have spark you will see it jump the gap. If there is no spark I usually jump a hot wire to the coil and check again. This will tell you where to look further. For fuel problems I first pull the fuel line off the carb and crank to make sure the pump is working. Remember that the generator fuel pump will not pick up any fuel if the coach tank has less than a quarter tank or so in it. If there is fuel there try and manually overide the carb choke or the carb linkage from the governor. Next thing to do is to make sure that the carb idle screw is set correctly, a good starting point is to turn the screw totally in clockwise then open it about 1 1/2 -2 complete turns. If all that is ok and it still does not start, do a compression check and rebuild carb. If you have not found the problem by then you might consider a trip to Alaska (might be fun) and bring it by my shop. Good luck.
Bill

Reading your question again I missed the part where the generator starts then stops. You could still be low on fuel or have a bad pump. so the fuel check is still good. You could also have a bad oil pressure sending unit so check that or install a new one. There could be an electrical problem in the oil pressure sensing circuit or a loose wire. If the new sending unit makes it run OK if not you need to look further. I think the sending unit opens the sensing circuit when the oil pressure comes up so you can accomplish the same thing by unplugging it. Unfortunately you need to pull the oil filter to do that. My feeling is you should completely check out the oil pressure circuit.
Sorry I went down the wrong track when I missread your question. Good luk.
Bill