Forum Discussion

nayther's avatar
nayther
Explorer
Sep 29, 2015

Onan Fuel Pump

Anyone ever substitute a generic fuel pump for the OEM unit? I'm having what I think are fuel delivery issues, generator runs for as long at two hours, then sputters and dies like its running out of fuel, changed filters and they were fine, still does it. No code beyond "unexpected shutdown" so its not going off on that and sure sounds like fuel starvation when it quits. Was thinking about one of the small solid state pumps but mounting it back near the tank so it pushes instead of pulls the fuel. OEM pumps are a bit pricey compared to these generic solid state units.

Thoughts?
Toy Haulers
  • darsben's avatar
    darsben
    Explorer II
    Sep 29, 2015
    others have reported moving the fuel pump off the generator to a cooler location cures similar problems
  • allcool's avatar
    allcool
    Explorer
    Sep 29, 2015
    What exact trouble code # did you get, and is it always the same trouble code # every time it stalls out...?

    Does it start right back up and run fine after it stalls out ?
  • DOITHARD's avatar
    DOITHARD
    Explorer
    Sep 29, 2015
    Had the same issues and replaced pump with Amazon aftermarket product...no issues thus far. Bought and extra pump just in case the luck of the Irish had left me.
  • nayther's avatar
    nayther
    Explorer
    Sep 30, 2015
    allcool wrote:
    What exact trouble code # did you get, and is it always the same trouble code # every time it stalls out...?

    Does it start right back up and run fine after it stalls out ?


    I've only checked the code once, don't remember the number but it stated "shut down for external reason" or similar and it surged for a minute or so prior to shutting off like the carb was running dry. It restarts after a cooling off period.
  • nayther's avatar
    nayther
    Explorer
    Sep 30, 2015
    Y-Guy wrote:
    I put in a generic from Amazon. Airtex E11015 Electric Fuel Pump for Onan Generator Set

    Fellow Toy Hauler Brenden had a good threat that listed various partes for the change. Click Here

    That's assuming you have an Onan 5500, not sure about exact parts for others.


    Thanks, I almost ordered one of those Airtex as it looks so close to the existing one. Rig is in Ridgecrest right now for our race this weekend, heading out there tonight so won't get a chance to do this until it comes home, might run to a local auto parts store and buy their generic one if the temporary Honda I have doesn't work out.
  • nayther's avatar
    nayther
    Explorer
    Oct 20, 2015
    nayther wrote:
    Y-Guy wrote:
    I put in a generic from Amazon. Airtex E11015 Electric Fuel Pump for Onan Generator Set

    Fellow Toy Hauler Brenden had a good threat that listed various partes for the change. Click Here

    That's assuming you have an Onan 5500, not sure about exact parts for others.


    Thanks, I almost ordered one of those Airtex as it looks so close to the existing one. Rig is in Ridgecrest right now for our race this weekend, heading out there tonight so won't get a chance to do this until it comes home, might run to a local auto parts store and buy their generic one if the temporary Honda I have doesn't work out.


    Did you just replace the pump in the same location under the generator? I was thinking about relocating it back at the tank, one so it's pushing instead of sucking, two so it isn't affected by the generator heat. Easy to do, just run one wire along with the fuel line (which I'm replacing with copper anyway as the all rubber one is so soft I'm sure the ethanol has attacked it like it did the fuel station pump inlet hose).
  • Gjac's avatar
    Gjac
    Explorer III
    Oct 21, 2015
    When mine went out on a trip I replaced it with one from Napa. Just look at the specs and make sure the flow rates are the same or higher. Mine was about $30 if I remember correctly. That was about 10 years ago.
  • azpete's avatar
    azpete
    Explorer
    Oct 23, 2015
    i have done it on many different models. all you need to know is the operating fuel pressure. any auto parts place can supply a generic pump already set at the needed pressure.
  • nayther's avatar
    nayther
    Explorer
    Oct 23, 2015
    azpete wrote:
    i have done it on many different models. all you need to know is the operating fuel pressure. any auto parts place can supply a generic pump already set at the needed pressure.


    I've got the pump, exact match to the OEM, my last question is in regards to location; should I just replace as is or relocate to the rear, close to the tank so it "pushes" instead of "pulls"? Also to isolate it from the heat. The existing pump works fine unless its 100 then it runs for about 1 hour until it can't keep up and it starves for fuel.

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