1. Hello there guest and Welcome to The #1 Classic Mustang forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

Stinky gas smell

Discussion in 'General Mustang Discussion' started by Mach1 Driver, Dec 7, 2017.

  1. Mach1 Driver

    Mach1 Driver Active Member

    In 1970 Ford started using charcoal canisters on cars sold in California. In 1971 they improved the system and put it on all cars. Initially it just worked on the fuel tank vent. As regulations became more stringent they had to pull vapor from the carb bowl vents as well. I'm not sure when this occurred, but as late as 1973 they still hadn't made any connections to the carb vents. My car is in good repair and I don't have any leaks, but if you run the car it will stink-up the garage for at least a week, and then it stops. Since nothing is changing with the fuel tank vent I have to assume the stink continues until the gas in the carb bowl evaporates.

    So that got me thinking about all you guys with EFI- do your cars stink-up the garage? The major contributor (the carburetor) has been eliminated. All that's left is the tank, and since it doesn't get that hot and the fuel is well contained, it shouldn't stink- at least mine doesn't. I'd appreciate hearing from you guys.
  2. kb3

    kb3 Well-Known Member

    I have zero smell coming from the efi system. The fuel system is sealed with no venting to the outside air. I think the gas cap allows air into the tank as the gas is drawn down.
  3. Mach1 Driver

    Mach1 Driver Active Member

    That's what I expected. I assume you haven't added a carbon canister, it's a 65, but with what engine and whose EFI? Is your pump internal to the tank or external, and do you have a return line or a command center? Since you built it from a shell you probably don't have any before/after experience with and without the carburetor?
  4. Horseplay

    Horseplay I Don't Care. Do you?

    I have a FiTech system on mine with an in tank pump set-up. My gas cap is not vented. I have a tank vent line with a pressure activated vent assembly. So the whole system is sealed unless excess pressure builds up in the tank due to heat and expansion or excess pressure the return fuel may create in the tank. When the car is off the whole thing is sealed tight and no fumes.
    Mach1 Driver likes this.
  5. kb3

    kb3 Well-Known Member

    Correct, no before experience. It is a 306 with the 1993 vintage Ford SEFI setup. External pump, return system, no canister. Again, no vent in the system as of yet....debated in another thread!
    Mach1 Driver likes this.
  6. Mach1 Driver

    Mach1 Driver Active Member

    I started this thread on a couple of other forums and got the same result- with EFI and no carbon canister, they have no gas fumes. Another plus for EFI.:cool:
  7. 69XR7RestMod

    69XR7RestMod New Member

    I also have a Fitech with a tanks inc pump. I added a carbon canister from a motor cycle to the vent line and the gas smell has been greatly reduced.

    Can you give me a part number for your pressure activated vent? What happens in your system when there’s vacuum from fuel being drawn down? I’d like to completely eliminate the gas smell in mine.
  8. Mach1 Driver

    Mach1 Driver Active Member

    Newton makes the TPV6 and another
  9. 3175375

    3175375 Well-Known Member

    I like gas smell
  10. KBMWRS

    KBMWRS What did the moron say today?

    That explains a lot when you are around people.:D:rolleyes:
  11. Horseplay

    Horseplay I Don't Care. Do you?

    We have a winner!

    This is what I used.
    The valve I used (Newton) opens in the case of increased pressure or vacuum so when running there is no impediment to fuel flow or return.
  12. Mach1 Driver

    Mach1 Driver Active Member

    Yes they open at .08 psi negative pressure to let air in, as fuel level goes down, and at .725 psi positive pressure to let air out as the tank heats.

Share This Page