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joe0508's avatar
joe0508
Explorer
Feb 13, 2014

gas smell

I have p30 chassis with a 454 tbi.Is it normal to smell gas when pushing the motorhome up hill with it in cruise.What could be causing this.I don't smell it any other time only when going up a mountain with it in cruise.Maybe I should let off the cruise and baby it up the mountain.

10 Replies

  • There might be a leak at the presure regulator, or depending on the amount of miles on the engine some of the intake valve stems are worn and are creating a back preure under severe load, this will allow fuel to blow back yust enough to create the small, you need to find that as soon as posible, there is a fire danger.

    Also check all the fuel lines giong to the thrtle body to see that none is loose or that there are no cracks where the lines are attached to the body, some times when mechanics overtighten the fitting they crack the tube inside and you do not see it until the unit is disconected and examined carfully, check that the throtle body is not loose or the it has not warped, it only takes a small opening for fuel to leak.

    Have the mechanic perform a leak down presure test on the engine it will indicate if the rings are good, the valve seals on the exhaust or the intake valve guides are leaking.

    It has been a number of years since I have done any vacum or fuel leak traicing on vehicles.

    Hope it helps a little.

    navegator
  • navegator wrote:
    You do not mention if it is carburated of fuel injected.

    If it is fuel injected have the mechanic spay a little water on the injectors to check the "O" ring seals, yust a little with a spray bottle, if the seals are dry and brittle the engine will stumble and get rough, that can be one source of fuel vapors, since the cruise control is trying to maintain a specific speed by increasing the amount of fuel delivered to the intakes.

    When you go uphill try to down shift out of cruise control, you are making the engine and the transmition work harder and eventually one of them is going to brake, most probable the transmition.

    navegator
    it is tbi.Throttle body injected.
  • You do not mention if it is carburated of fuel injected.

    If it is fuel injected have the mechanic spay a little water on the injectors to check the "O" ring seals, yust a little with a spray bottle, if the seals are dry and brittle the engine will stumble and get rough, that can be one source of fuel vapors, since the cruise control is trying to maintain a specific speed by increasing the amount of fuel delivered to the intakes.

    When you go uphill try to down shift out of cruise control, you are making the engine and the transmition work harder and eventually one of them is going to brake, most probable the transmition.

    navegator
  • JJBIRISH wrote:
    that isn’t normal, get it checked out by a good mechanic, and practice daily fire drills until you get it figured out…
    I am sure you know what gasoline smells like but are you sure it’s not oil leaking on the manifold or something like that…
    no it is gas fumes I'm smelling.I only. Smell it when it is straining up hill.
  • that isn’t normal, get it checked out by a good mechanic, and practice daily fire drills until you get it figured out…
    I am sure you know what gasoline smells like but are you sure it’s not oil leaking on the manifold or something like that…
  • tatest wrote:
    No, and if the filler is at the back of the fuel tank, that would be one of the first places I would look for a leak.
    I smell it in the front and that is where the engine is at.I never smell it only when pushing it up a hill.
  • No, and if the filler is at the back of the fuel tank, that would be one of the first places I would look for a leak.
  • I would get it checked out and then take it easy going up the hill anyway. It's better for it.
  • Gjac's avatar
    Gjac
    Explorer III
    I have never smelled gas in 70k miles of travel with my P-30.
  • No gas smell is normal. You may have an intermittant leak only under strain. A mechanic should be able to pinpoint the problem for you.

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