Fuel pump clicks-off 2 gallons from being 'full'.

Discussion in 'Gen 2 Prius Main Forum' started by George W, Jul 25, 2019.

  1. George W

    George W Active Member

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    Recently my Prius has begun an intermittent issue of stoping the pump prematurely. After the fuel nozzle is triggered 'off', I can remove and then reinsert the nozzle to fill two more gallons before the nozzle is triggered off again.

    I've seen forum threads where the fuel bladder can burp, or vary its capacity according to weather. I haven't yet seen a thread where so fuel nozzle is triggered that early.

    I'm the third owner of this Prius and have driven it for about a year before this issue began. Any thoughts as to what could be going on? Thank you.
     
  2. PriusCamper

    PriusCamper Senior Member

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    There's a rubber bladder inside the gas tank in Gen2 to reduce gas emissions when refillling... The idea was that unlike a normal empty gas tank, a collapsed bladder has no air inside so when the gas is filled there's no polluted air displaced by the gas going in to the tank.

    When Gen2 run was over and they came out with Gen3 Prius they discontinued this design because in cold weather a bladder wouldn't stretch out consistently and in some cases vommit gas back out the fill spout. In other cases such as yours the bladder gets old and loses capacity and also makes it hard for the gas gauge to get a good reading.

    The best fix I've found for this is long road trips in hot weather and filling the tank as full as possible and drain it down to close as empty as possible and then repeat. Another option is to keep your tank as full as possible, especially in winter months when the bladder is less elastic.

    Also some gas pumps, especially newer pumps are way more sensitive than other and will shut off early... And I've found that the higher the pressure of gas going in the more likely it shuts off early, so if you're at a station with a 1/2 dozen people all pumping at the same time you might find it easier to fill than when you're the only person pumping at the same station.
     
    #2 PriusCamper, Jul 25, 2019
    Last edited: Jul 25, 2019
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  3. Skibob

    Skibob Senior Member

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    I set the nozzle to the lower setting myself. That seems to help. The tanks so small the lower flow will still fill the tank faster than the pickup trucks around me.
     
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  4. George W

    George W Active Member

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    Thank you both for your responses. Setting the pump handle to its lowest click stop has helped reduce this error, but my concern is, why now after over a year of ownership? I can't think of anything maintenance wise that has changed to account for it.
     
  5. bisco

    bisco cookie crumbler

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    sometimes it is weather related, sometimes pump related, sometimes, the bladder just has a mind of its own, kinda like mine :unsure:
     
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  6. Calimobber

    Calimobber New Member

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    Yeah the bladder just triggers an early shut off. I do the same thing some times.
     
  7. Skibob

    Skibob Senior Member

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    Your assuming the problem is with your car. How do you know the gas stations you frequent haven’t installed higher volume pumps? Higher volume pumps seems to be the thing to do these days. Quicker out the more people can pump gas
     
  8. PriusCamper

    PriusCamper Senior Member

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    When I'm in Oregon where they won't let you pump your own gas I always tell them, "please fill it as full as possible because it always shuts off early before it's full." Of course there's a law in Oregon that doesn't allow topping off the tank so mostly I prefer to not buy gas in Oregon.

    When I pump my own gas, I prefer crowded gas stations where all the pumps are running at the same time because the pressure going in to the tank is low. And the very best way to fill is pre-pay, because the pump in the last 1/2 dollar will pump much slower than you can pump with the hand lever. The trick is to get your tank to hit full right before that super low flow pumping, which is not easy.
     
  9. George W

    George W Active Member

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    Great Idea. Thanks for that reminder.
     
  10. George W

    George W Active Member

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    Because of my lack of experience I always assume anything Prius-related is my doing.
     
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  11. The Electric Me

    The Electric Me Go Speed Go!

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    I live in Oregon, and that law is basically unenforceable.
    I never had the rubber gas bladder, even my Prius was Gen 3.
    But in Oregon, I can be at a pump covered with stickers saying "Don't Top Off" and in most cases, unless I specifically say something, they always top off. I don't want them to, and they most often do.

    It's a pet peeve of mine. I'm to the point where I really wish Oregon would allow us to pump our own gas.
    What is really frustrating to me, is my experience is...that if I don't say anything, and go inside to pay, they will ALWAYS top off the tank, to some nice even number.
    If I politely mention to the station attendant "Please don't top off"....I inevitably get a look of disdain and the annoyed exclamation that they "Never Top Off".

    Right now, it's basically only Oregon and New Jersey that don't allow you to pump your own gas. I kind of wish Oregon would join the rest of the United States and just allow me to fill the tank as I wish.
     
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  12. Skibob

    Skibob Senior Member

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    What happens if you pump your own gas?
     
  13. bisco

    bisco cookie crumbler

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    they hang you
     
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  14. The Electric Me

    The Electric Me Go Speed Go!

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    Well if you were born and raised here? You're probably just pretty use to NOT pumping your own gas.
    And the way it is at most stations, you pull up...and the attendant is there, you don't have the chance to pump your own gas.

    The arguable flip side is.....that you don't have to pump your own gas. Which sometimes can be a nice convenience.

    But since I think all modern cars today, specifically warn against topping off, and I can't trust the attendants to NOT top off, I've reached the point where I think I'd rather have the independence to fill my own gasoline.

    Way back in 2009-2010 when I was first considering Prius, including the last model year of the Gen 2, with the gas bladder, the self serve nature of Oregon's gas stations was a factor in my waiting to get a Prius.
     
  15. PriusCamper

    PriusCamper Senior Member

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    I didn't know you lived nearby? I'm of similar sentiments... But haven't you run into attendants more interested in rounded off numbers on the final price? Or one time when I pre-paid the guy used it shutting off early as a way to get me to say "keep the change." Lol, that didn't make me happy, especially when he's like, sorry, the pump already is shut off. I'd have to reset it and start over with the less than a dollar you want in there.

    Or then there's the delusional power-hungry pump attendant... One time I was entering my credit card info to speed up the transaction and the attendant screamed at me: "Don't touch my pump!"

    Lol... I wonder what will happen first, pumping our own gas in Oregon, or finally buying a Tesla and never worrying about a gas pump again?
     
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  16. Raytheeagle

    Raytheeagle Senior Member

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    Is that what those wooden platforms are for out back:p.
     
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  17. George W

    George W Active Member

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    Now the Tesla attendant can scream at you for charging too long
     
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