Gas tank pressure


  • Gas tank pressure

    It seems here lately that the gas tank has been building some serious pressure… I went to get gas today and, in removing my gas cap there was so much pressure that gas came rushing out .. I tried a new gas cap but that didn't seem any better .... Any one have any idea what might cause this ????
    D@MN IT FEELS GOOD TO BE A GANGSTA

  • #2
    Uh oh. Now i'm scared. My cap always lets loose of a big long sighing hiss when i take it off on a hot day or after a long drive.
    My beloved Z:1987 2+2 NA2T w/30a swap.
    My black sheep: 88ss parts car (pretty much stripped and gone)
    207k miles and counting. Turbo'd since 155k.

  • #3
    Yes it caught me off gaurd.... It has been like this since i got it and it is has been getting worse.... The gas shot out like two and a half foot… scared the hell out of me.... :shock:
    D@MN IT FEELS GOOD TO BE A GANGSTA

  • #4
    your vent line is plugged?

  • #5
    Do you remove it slowly? That is a crap load of pressure. Definetly check your evac. stuff

    Terrible idea putting those wheels on…

  • #6
    G-E wrote: your vent line is plugged?
    That would be my first guess.

    HP air can do wonders. :wink:
    Just stand back and throw money.
    Performance costs money.
    Reliable performance costs more.

  • #7
    If you have this problem and eleminated most of your emissions crap, hook up a one way fuel filter to the evaporation lines. Mount it in a position distanced above the fuel tank to avoid spilling gas while cornering hard.

    Pressure inside the tank will be relieved and the one way valve will keep outside debris from entering.

  • #8
    yes i remove it slowly … now… if not gas shoots out.... I am going to try to drop that tank this weekend and work foreward … hopefully i will find the source ....
    D@MN IT FEELS GOOD TO BE A GANGSTA

  • #9
    84z2+2 wrote: yes i remove it slowly … now… if not gas shoots out.... I am going to try to drop that tank this weekend and work foreward … hopefully i will find the source ....
    If you dont want a headache later, when you drop your tank, you can use a sawzall to cut a access hole so you can get to your fuel pump and all of the lines.

    This way later when you do stuff you wont have to drop the tank again.

    Oh also, in one of the manuals it says NOT to remove the filler neck from the actual tank do to the fact that it wont seal right after you do. Thats what it says, dont know for sure if its true but I just drop the tank with the filler neck still attatched.
    85 Z31 6.0 LSX turbo 766whp/792wtq
    04 GTO, LS6, big cam, porting, N20… underway for summertime daily driver.

  • #10
    SATAN wrote: Oh also, in one of the manuals it says NOT to remove the filler neck from the actual tank do to the fact that it wont seal right after you do. Thats what it says, dont know for sure if its true but I just drop the tank with the filler neck still attatched.
    Thats what I do. No problems.
    Chuck Stong
    300+ Parts and Performance owner
    http://www.300-plus.com
    2002 ZCOT president and always active member

  • #11
    you more or less have to keep it attached so you don't spill any gas.... and the filler retainer ring is easy to undo