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txnese's avatar
txnese
Explorer
Dec 19, 2017

Generator problem??

I was using my Onan 4000 for a 4 hour trip, no issues. Tried starting it the next day, and it wouldn't start. I drove home without using it. Tried starting it again and nothing, but I did get a code 36. After googling for hints. The next day, I took of the fuel line and checked for fuel by pressing down the primer. It was getting fuel, so I tried starting it again. Fired right up and stayed running for almost an hour, before I turned it off. Came back a few hours later and it fired right up again. Any ideas?

8 Replies

  • Seems like a good diagnosis, I've been replacing various dry rotted rubber parts the past few months anyhow. I'll order one and throw it in. Can't really lose on changing out a $50 dollar part. It's probably original anyways. Thank you.
  • I went round and round just like you did. No firm one symptom to point at what to repair or replace.

    Until I finally found a competent repair guy.

    He said the rubber for the fuel pump gets unseen tiny cracks in it. Owners can't see it many repair guys don't know to look.

    Explains the stops and some starts and then none. He pulled it out and spread it out and you could see all the small cracks in the fold just waiting to get bigger. Ordered new fuel pump.

    AND

    In my case he crawled underneath when he got there to look at the fuel lines and what he 'also' saw was I had WAAAY too much fuel line. He said that fuel line was way too long and looped and turned all over under my coach. Said it looked like installed from the manuf. :R

    He cut a substantial amount of fuel line off and put new fuel pump in and have had not one problem with it since.
  • downtheroad wrote:
    Vapor lock maybe?
    It's working now so all is good.


    All is not good. My first thought was a filter issue. Clogged fuel filters often are misdiagnosed. I would find and replace the fuel filter servicing that line. I would cut the filter open after drying it out for a few days to confirm my suspicion. It's always easier in the driveway at home than in the rain at a campground.
  • When it wouldn't start, did you prime the engine by holding down the stop switch?

    Tom
  • Maybe the choke was stuck full open, that is what happens with our 2004 vintage.
  • DrewE's avatar
    DrewE
    Explorer III
    Did you buy gas between when it didn't work and when it started working again? Maybe the fuel level was simply too low in the tank.

    Code 36 is somewhat of a catch-all saying it didn't run or stopped running, I believe, due to some unidentified cause. Basically, it's what you already knew.