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MTK46 · 01-22-2019, 09:21 AM

My new to us 2011 MS 5th wheel came with a propane 5500 Watt Onan generator. Starts & runs fine for 1/2 hour or so then dies out like lack of fuel.
Have checked propane tanks have propane. Let sit for 5 min. starts right back up runs for 20 min. or so & does the same thing. Not setting any codes just starts running slow & dies like lack of propane.

Any ideas where to look?

bigchick · 01-22-2019, 03:50 PM

wow, that's hurting the brain.

my first guess would be fuel related, especially since you say it starts to run slow rather than just abruptly shutdown. but 20 and 30 minutes of running before it starts to slow seems to imply that it is getting fuel. it's possible the propane regulator near the tank has some type of issue that is causing it to supply less fuel / pressure as time goes on. i've heard of them freezing but i do not know how to test for that. that 5 minute break after it stops and before it is restarted may allow the regulator to rebuild pressure. but this just a guess and i have no idea how to test it. by chance is any other propane device coming on which is causing the generator to be starved for fuel? perhaps the refrigerator running on propane or the water heater? what happens if you are running the generator and then go turn on all the burners on the stove. does that starve the generator of fuel? there is a propane shutoff solenoid on the bottom of the generator. it opens when the generator is running. perhaps it is failing. again i have no idea how to test it.

MarcsBigfoot · 01-22-2019, 06:13 PM

Plug in a DVOM (volt meter). See if 120 volts goes to 0 then the gen shuts off or still has 120 v and engines dies. One will be the voltage reg and the other fuel or spark.

**Spdracr39** · 01-22-2019, 06:24 PM

If you open the tanks too fast they can trigger a safety device that will limit the flow. Perhaps the limited flow will supply enough propane to run the generator for a bit before the pressure drops too low. Try closing the tank valves then open them very slowly to avoid tripping the safety.

Chief Alen · 01-22-2019, 06:30 PM

Got a low oil sensor ...might not look like its low on the stick, got to be full .

Maybe disconnect and run it.

MTK46 · 01-24-2019, 09:07 AM

Did some testing last night after work. Found my propane regulator valve at the tanks bad. Have a new ordered from eBay. Hope that will fix my problem.

bigchick · 01-25-2019, 06:14 AM

i'm sorry, i forgot all about this. i had a possible fuel related issue with my 5500 lp generator. a technician told me to change the fuel source feeding the generator to see if that had any effect. there is a flared fitting down on the side of the generator where the fuel line connects to it. he had me take the existing fuel line off at that connection and then hook up my barbecue tank to the generator using the tank, regulator, and fuel line from the barbecue. then fire up the generator and see how it runs. but it sounds as if you found the problem with the regulator. what you found seems totally consistent with the problem you were having. best of luck

danhannah · 02-04-2019, 12:59 AM

You got to watch this Youtube. It fixed my problem 100% and many others as well. It is a problem with oil foaming.

Hope it works because boy is this a cheap fix!