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turbojimmy's avatar
turbojimmy
Explorer
Mar 24, 2014

1984 P30 Chassis - Gas Cap?

I bought this thing with a blown engine. One of the first things I did was try to get the generator going. It wouldn't run off of the feed from the fuel tank. I figured the fuel was bad (had been sitting for 6 or 7 years). The generator works fine running off of a gas can.

Long story short, I accidentally found that the generator runs out of fuel when the fuel tank gas cap is installed. It will run all day long if I take the gas tank cap off. Kind of makes sense now that I think about it. I used a hand-pump to try to get a siphon action going from the fuel line up at the fuel pump. It wouldn't work.

So what's the problem? Is it the wrong cap or a bad cap? Should it be vented? I *think* new gas caps create a seal and the venting is done through an EVAP system, which this vehicle does not have.

44 Replies

  • You may be on the right track on the gas cap.

    I had a '87 P30 with a 454 and had the same problem, someone stole my gas cap while also stealing my gas, I replaced it and had the same problem. My Brother, a mechanic suggested that I replace it with a vented cap. I then replaced it with a vented one and had no more problems with the generator.

    They are cheap and may be worth the experiment.
  • enblethen wrote:
    Your genset's fuel pump could be weak.
    The rubber line from tank to metal line could be collapsing.
    Fuel filter could be clogged.


    I have a new filter but I haven't installed it yet - I'm hoping that might be it.

    Stupid thing ran for 2 hours. I shut it off for about half an hour to install a new hour meter. Went to restart it and it wouldn't run. Used a MityVac to suck some fuel up to it, and it fired up and ran like it should. New hour meter didn't.
  • Your genset's fuel pump could be weak.
    The rubber line from tank to metal line could be collapsing.
    Fuel filter could be clogged.
  • You need enough gas in the tank to reach the tube. The pick up tube on the Jenny sits above the bottom. This ensures you have gas left to drive out from where you are camping. Today my Southwind Jenny stopped running ewhe the gauge was just above 1/4 th tank