Onan 5500 Shuts down?

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Meter Tech

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2007 WW 5th wheel with Onan 5.5HGJAB with 1,511 hours on it.  

Generator starts fine, after 20-30 minutes start to surge then shuts down. I get a Code 33 which doesn't seem to exist according to the Cummins owner's manual? 

Online search comes up with overheating.....but it's air cooled.....Go figure! Checked airflow and all good.

Some say oil to low, some say oil to high...tried that no change.

Going to change the fuel pump, filter and spark plugs next as all of these suggestions come up as well. 

Anyone else have this issue and if so what did you do?

:cheers:  

 
Check the fuel lines and the fuel filter

could be clogged - also run a healthy amount of seafoam in it to clear  any gunk in jets and around float

:poule:

 
Poule43 said:
Check the fuel lines and the fuel filter

could be clogged - also run a healthy amount of seafoam in it to clear  any gunk in jets and around float

:poule:
Click to expand...
Ya, I run Seafoam in every tank. Going to check fuel lines as well. Thx

 
Meter Tech said:
2007 WW 5th wheel with Onan 5.5HGJAB with 1,511 hours on it.  

Generator starts fine, after 20-30 minutes start to surge then shuts down. I get a Code 33 which doesn't seem to exist according to the Cummins owner's manual? 

Online search comes up with overheating.....but it's air cooled.....Go figure! Checked airflow and all good.

Some say oil to low, some say oil to high...tried that no change.

Going to change the fuel pump, filter and spark plugs next as all of these suggestions come up as well. 

Anyone else have this issue and if so what did you do?

:cheers:  
Click to expand...
Call Vito, he's mobile and the Onan guru. I think you're not diagnosing the code correctly.

(760)840-9106

 
Same issues, and oil level fixed it. Can't go by the dipstick. Level has to be at about 20% of the crosshatched area. Not at the top or too low. Crazy, I know. Not saying that's your problem but it was mine. Once it burns down and shuts down, I already know. I just add a little more and good to go again. Good luck. 

 
fuel pump...mine would do the exact same thing and apparently in 2007-2008ish there were some onan fuel pumps that had issues overheating. i finally replaced the pump after doing everything else.

 
Chingon619 said:
Same issues, and oil level fixed it. Can't go by the dipstick. Level has to be at about 20% of the crosshatched area. Not at the top or too low. Crazy, I know. Not saying that's your problem but it was mine. Once it burns down and shuts down, I already know. I just add a little more and good to go again. Good luck. 
Click to expand...
Tried that, didn't seem to do anything....frustration is high!  :banghead:

 
Also, check for proper tank venting. It may run until it starts pulling a vacuum, and quit. Verify venting and/or run it with the cap off.

 
They are a standard fuel pump,  the one i replaced mine with was from Orileys and worked way better, did the 3lb fuel pressure 

 
Probably not related but I just swapped the China carb AGAIN and I've now got a running 4000 in my, new to me, 2003 Rampage.

It would run but cut out quickly, especially with load. 

Last time the carb gaskets gave me a nightmare so this time I lightly applied RTV to keep them in place.  

 
https://www.amazon.com/gp/product/B07CVWX3VB/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1    i would shut it down normally and open the bowl drain and drain the fuel out into something so you know how much fuel should be in the bowl. then i would restart it and wait for the shutdown then drain the bowl again and observe the amount that comes out. if it still has a good amount of fuel unplug the oil sender and start if the sender is unplugged it wont shutdown from low oil pressure or a faulty sender. also on the bottom the carb there there is a plug that is the anti dieseling solenoid the also go bad and they shut the fuel off by plugging off the jet. if it is bad you can cut the pin out of it and put it back in but you have to shut it down when its cool otherwise it will diesel and not want to shut off

 
Last edited by a moderator:
I had the same trailer and same genny with the same issues. It drove me nuts and I could fix it to make it run for a little while longer by pulling the fuel filter and draining it and the pressure then repriming and good to go… 

Then got home and I did as said above, I took the carb out, soaked it, sprayed it out with carb cleaner and did a thorough cleaning, then I ran sea foam through the tank. When I put it back together it fired right up and never ever had any more issues. You could get a new Chinese carb but you’re better cleaning the original, imo 

 
good info, im going to pick one up and keep it in the TH for when/if it happens. 

 
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