Generator issue. XLR 425

[duallyd]

So, tank is full of gas, have started the generator, and it will run for 5, 10, 15, or maybe even 30 minutes, then just shut off. There's no rhyme or reason, but it will not stay running, shuts off.

Am I missing something about these Onan / Cummins generators? Rv is a 2015 425 thunderbolt.

We live full time, and I'm only exercising the generator, but it will not stay on. Info, will be much appreciated.

Jon

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[Sayitdog]

It might be your fuel tank vent hose, my vent hose was installed under my fill hose and it would fill with gas and when i tried putting gas into tank the pressure kept shutting yhe pump off. The next time it shuts off try taking off the fuel cap and see if you hear and or feel air coming out or ryshing in. If your tank is not venting or your cap isnt then it might be building up vacuum which evevtually might be more than your fuel pump can pump.

[R3Jones]

Have you checked the error code? That will help narrow your focus.




-R.Jones
Nitro 31FQSL

[duallyd]

Code 36, fuel. Checked the vent placement, it's fine. Disconnected it just to make sure it was clear. Unscrewed the carb drain, no gas. Ran the primer pump, no gas. I'm guessing the fuel filter may be plugged, or pump is bad. Pump runs, tried it several times. Any other ideas? Generator has 1.4 hrs on it.

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[R3Jones]

I had error code 36 two times as well. The first time it occurred my fuel tank was too low. The second time my fuel filter was clogged by plastic debris. Presumably from the gas tank drilling.




-R.Jones
Nitro 31FQSL

[jkweller]

I have a 2015 Spartan toyhauler with an Onan Marquis Gold 5.5k gas gen and am having the same problems. I have over 50 hrs. on the gen. and I just got it back from the certified Onan service center after them having it for 25 days and this is what they found. They did 4 hrs of diagnostics and came up with the gen is over heating and shutting down causing the code 36.
Now the sad part. Onan says that even though I am in my warranty period overheating is NOT a warranty issue. So that being said I'm responsible for the $597.70 bill!!!! It's not a warranty issue but in the next statement they tell me they have a "hot air recirculation kit" for
$300.00 . They wouldn't have come up with this kit if they didn't know there was a problem.
I don't get it!! Onan say's they didn't cause the problem , the problem was caused by Prime Time and the way they installed the gen. which Onan say's is a factory defect!!!
I plan to talk to Prime Time at the Frog Rally next week. As a consumer I've just about had it. Onan blames Prime Time and we'll see what Prime Time say's.
I hope this helps you and I'll let you know the outcome from the rally.

[BBQGUY]

Cutting off in 5 minutes is not caused by overheating. Most likely a clogged fuel filter, or a bad fuel pump, trash in the tank getting in the fuel pick-up, blocked vent on the vapor canister, crimped/clasped fuel line...


If the unit is overheating, try leaving the compartment door open.
The overheating kit is an air diverter that is placed under the generator to separate the intake air side from the exhaust side.

[jkweller]

I was trying to keep my post as small as I could but my gen usually dies anywhere from 20 mins to an hour depending on the outside temp. The longest I have ever had it running at one time is 2 hrs. and it was in a rest area in Fla and the temp was 72 degs and humid. Had I known an Onan gen couldn't handle that I would not have purchased it.

[Zburnoutking]

Had same problem with my 395 from the time I brought it home. Long story short I ended up with adding 2nd fuel pump near the fuel tank. Sucking gas almost 40' is not ideal especially when it's hot.

Also added air deflector under generator to redirect hot exhaust air from intake.

Results are good.

[togo444]

I had that problem too on my 5500 Onan. I bought a new fuel pump and it has worked great ever since.


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[weatherguru1]

Mine had SAWDUST, yes "sawdust" in a perfectly clean, new unit. I have the pictures from the service department to prove it. Any guesses how it got there?

[TechBeckster]

Mine turned out to be the carb...Had to replace it, no rebuild kit. I was told by onan to use gas without ethynol...

[wrsmsgt]

Dealer suggested cleaning needle valve on bottom of carb. Seeing it is about impossible to remove with pulling carb off I disconnected the fuel line ran the carb cleaner cans hose up the inlet and sprayed it full of cleaner. Fixed the problem of running awhile and shutting down

[Mainous]

Been fighting the same random shutdown code 36 issues. Finally replaced Onan pump and filter today only to have the same symptom. Ended up putting this back at the tank and problem solved.its just too long a run with rubber fuel line.

[Kilday4]

The fuel pumps are notorious for going bad. They are cheaply constructed imo. I've heard of pumps going bad in just a few uses. I agree with others that the length of draw from the tank is too much for the small pumps. My neighbor had same issue with his 4K Onan and replaced the fuel pump with an aftermarket brand because Onan's replacement was on back order for several weeks. I personally have had no issues with our 4K but I use a fuel stabilizer and exercise it regularly when it sits at home. The carburetors are another issue too. Worst thing for these units is to just let them sit. It amazes me to see the problems people have with a product by a company that has been around for decades. Best of luck


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[duallyd]

Originally Posted by Mainous

Been fighting the same random shutdown code 36 issues. Finally replaced Onan pump and filter today only to have the same symptom. Ended up putting this back at the tank and problem solved.its just too long a run with rubber fuel line.

Can I ask what the make/model of the new pump are? And did you remove the oem pump, or are you using both? Thanks

[Mainous]

Not sure if you are asking me. But the pump in my pic is a Mr. Gasket 42S. It's low pressure pump and I left the original internal pump in place. I wired it into what would have been the circuit for the fueling station since I ordered my 31 fqsl without one. BTW... no more issues since making doing this mod.

[340xlr]

Great info to keep in mind for sure. Used our genny for two days last Labor Day with no issues. And just periodically run it otherwise. It does use the fuel for when running the ac or under load.

[duallyd]

Originally Posted by Mainous

Not sure if you are asking me. But the pump in my pic is a Mr. Gasket 42S. It's low pressure pump and I left the original internal pump in place. I wired it into what would have been the circuit for the fueling station since I ordered my 31 fqsl without one. BTW... no more issues since making doing this mod.

Yes, I was asking you, and thanks. I will be doing this mod in the spring. Sometimes, especially in the colder weather, mine will run and not miss a beat. Seems to act up more in the warmer months. Haven't used it, as a soul source of power, as we currently full time and are powered thru the campground. I have been running it periodically, just to keep it from gumming up.

Also, what about the fuel filter I see on your new pump?

[DennisTD]

Our Onan (4400) in our 29HFS quits on very hot days after about 45 minutes of running. I'm sure it's running out of fuel, from either a bad/marginal fuel pump or vapor lock or both. The way XLR installed it the fuel lines enter the compartment on the opposite side of the fuel connection, then have excess line running up and around and over the genny. The fuel line is HOT by the time it gets to the generator! I am going to re-route the lines so they enter the generator compartment right at the fuel connection to the generator and see if that helps. If not I might try that extra fuel pump noted above.