Gas Fuel Gas Cap no Hiss

Posted by azkkr, Aug 30, 2007

Please Support VR Speed Factory
  1. azkkr

    azkkr Proven Member

    53
    0
    Joined Aug 21, 2005
    suwanee, Georgia
    96 TSI

    Whenever I open my gas cap, I never get a "HISS" or pressure release from the tank. I heard, I am supposed to but, I never get this "SOUND", neither with full tank nor empty.

    Is this normal?
     

    Log in/Register to remove ads
  2. 90 Eagle Talon

    90 Eagle Talon Probationary Member

    20
    0
    Joined Jul 26, 2007
    Margate, Florida
    I think it depends on how hot it is when you fill up, if you leave you car to bake and then go open it I guess it should but if you fill at night when it is colder it probably will not at least it is like that here in florida it is hot down here.
     
  3. DGajre777

    DGajre777 DSM Wiseman

    3,782
    89
    Joined Jul 16, 2004
    Orlando, Florida
    My DSM:
    Loading...
  4. azkkr

    azkkr Proven Member

    53
    0
    Joined Aug 21, 2005
    suwanee, Georgia
    I bought a regular cap last weeK. I do not think is pre-vented. I am asking because I am trying to fix a problem with the evap circuit. I check the voltage on the ecu to see if the Canister selonoid for the Evap was being grounded. The Volt reads about 13 V but never ground(never goes to 0). I got another ECU thinking that was the problem, but same thing happens. I am getting a P0446. I check all the vacuum lines, the canister, replace the solenoid and the purge valve, the ECU but still get the code. Therefore, I thought that maybe I have a vapor leak form the tank or the hoses but everything looks OK. No small of gasoline anywhere.
     
  5. DSM90AWD

    DSM90AWD DSM Wiseman

    2,638
    89
    Joined Dec 22, 2002
    Bear, Delaware
    I assume you also checked the evap line comming in from the tank and the checkvalve? :dsm:
     
    My DSM:
    1990 Eagle Talon TSi AWD

    11.899 @ 122.410 MPH
    Loading...
  6. romeen

    romeen DSM Wiseman

    2,434
    29
    Joined Jul 12, 2006
    Vancouver, Washington
    I am having the same problem with no pressure buildup whatsoever in the tank as well as a P0455 code. This thread was very helpful to me.

    http://www.dsmtuners.com/forums/showthread.php?t=259430

    I ended up pressurizing my fuel tank via an air compressor hooked up to the EVAP line (where it comes into the engine bay) and listening for the leak. It turns out that I have a vacuum line (about 1" diameter) on top of the fuel tank at the rear that is disconnected. As fast as my helper could pump air in I could feel it rushing out of here. Since it's on top of the tank I couldn't visualize or even feel where it is supposed to be connected to. So next week I will have to drop the tank for this otherwise simple fix.

    This may also help. Post #7 shows a good schematic (compliments of luv2rallye):

    http://www.dsmtuners.com/forums/showthread.php?t=259173
     
  7. forged_tsi

    forged_tsi Probationary Member

    12
    0
    Joined Nov 23, 2009
    lynnwood, Washington
    i have a similar problem where i have no hiss.. however i removed my emissions including blocked off egr.. i think i may need to cap something off for the evap canister.. ? could this be causing the problem? also im getting horrible mpgs since emissions were removed.. i didnt pay attention if there was a hiss prior..

    also, when i was searching for a mysterious wet carpet cause.. i found gas under my rear seat.. and the plug was missing.. if i fill up and top it off i get a gas smell.. could a line be busted on top of my tank as well? maybe the previous owner had it out for some reason. i have no idea..

    its a 91 talon TSI FWD btw..
     

Share This Page

Loading...


Log in/Register to remove ads

Support Vendors who Support the DSM Community
Ace Race Parts Advanced Fuel Injection Archer Fabrication Boostin Performance ECM Tuning Extreme Turbo Systems ExtremePSI Feal Suspension Fuel Injector Clinic Jacks Transmissions Jackson Auto Machine JNZ Tuning Magnus Motorsports Miller Import Parts Morrison Fabrication & Design OHM Racing Race Components Inc RockAuto RoadSurge Spultronix Performance STM Tuned Strictly Import Motorsports VR Speed Factory