1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Gas fill vent

Discussion in 'Gen 3 Prius Main Forum' started by Therapydoc, Dec 4, 2023.

  1. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    24
    8
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    Where would one look for the vent for the gas fill? I fight this thing off and on when driving on County roads or in the winter with snow. I am assuming something keeps blocking the vent because the gas pump shuts off after about a quarter gallon all the time and I have to manually slowly add gas in.

    I’m going to have to modify where the vent comes out or something
     
  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    22,759
    14,798
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    You can find a couple diagrams on the Gen 3 stump-the-chump thread.

    This one is schematic, to give an idea what components are present and how they are connected. It is only approximate as to where they physically are:

    [​IMG]

    Notice it shows the "air filter" right up against an air inlet port located right with the filler neck.

    That is where the port is, but it's not really where the filter is. The filter is the thing with the blue ? here. Callout *4 is the "air inlet port":

    [​IMG]

    Notice there's quite a bit of stuff involved. The vapor you displace from the tank as you fill passes through the fuel fill check valve and fuel cut-off valve, follows the tank vent line into the charcoal canister, exits from there through the vent valve and the air "inlet" line (not so much an "inlet" while you're fueling), and out through the filter and the air "inlet" port.

    Obstructions anywhere in that path could explain the symptoms.

    Does this car have any history of fill-ups being "topped off"?
     
  3. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,013
    9,999
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Does this system have the flow capacity to handle the air displaced during a fill? Or just the evaporation later?

    P.S. How are you managing to post images this week? With the ongoing server migration issues, I'm not currently successful with attempts to include pictures.
     
  4. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    22,759
    14,798
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    I haven't tried uploading any images, only placing [img] links to images already existing.

    That seems to be working ok for images hosted elsewhere than PriusChat, and also for images on PriusChat if I enter a direct URL (not one involving proxy.php). The URL in the resulting post ends up involving proxy.php, and the original image has been newly cached so it works.

    I reported a problem where existing posts with proxy.php links to images that had been cached before the migration were busted. Don't know if that's fixed yet.

    I think the EVAP/ORVR (onboard refueling vapor recovery) system does indeed handle the air going out during refueling. That has to pass through the charcoal canister, to make sure you're venting out just the air and not the HC vapors.

    This diagram is for Gen 2 (warning Will Robinson, this diagram is for Gen 2)—you can tell by the bladder in the tank—but it gives a bit more explanation of the system.

    [​IMG]

    In Gen 2, only what escapes from inside the bladder has to go through the canister; that then proceeds into the space around the bladder and out the Canister Closed Valve and Fresh Air Valve. In Gen 3 without the bladder, all the air leaving the tank is vapor-laden, so all the more important that it go through the canister on its way out.
     
    #4 ChapmanF, Dec 4, 2023
    Last edited: Dec 4, 2023
    fuzzy1 likes this.
  5. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    10,642
    4,318
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Cut and paste function still works for images...
     
  6. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    24
    8
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    never been topped off since I’ve owned it. When gas pump kicks off, it’s removed. I fill up every two days so that’s why it’s a pain in the nice person. It’s my work car.

    i had this same issue about a year ago and i washed the heck out of it around fender well and all and took things apart and never really found anything in particular but it started filling correctly again so I let it be.
     
  7. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    24
    8
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    It is a gen 3 2015 model. I inspected the charcoal canister and did a check last time and everything was the way it should be.