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Trouble putting gas in your Volt

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Just wanted to share this story in case anyone else is wondering. I admit, it was my fault, but

I stopped to get gas and press the button to depressurize the gas tank. I removed the gas tank cap and proceeded to put my credit card in the gas pump and gas up. I was unable to gas up because the store was changing shifts and had the all pumps turned off. Being impatient and lazy, I simply got in my car and drove to the station next door without putting the gas cap back on or shutting the gas lid. When I got to the station next door, I did not push the gas tank release button because I did not put the gas cap back on or close the gas door. I did the payment thing and inserted the gas pump nozzle in the gas tank. Every time I squeezed the gas pump handle, the gas pump handle would cut off as though my tank was full. At first I though maybe I was pumping too fast, but no it continued to cut off regardless of how slow I pumped. I finally realized that even though I did not put the gas cap back on and shut the door, I still had to push the gas tank release button again. I pressed the gas tank release button and everything was fine and I filled up. Apparently there must be another valve that allows the gas to flow from the gas tanks' input nozzle to the tank itself and turning your car on closes it regardless of whether your put the gas cap on or not. I though the gas cap held the pressure, but apparently not.

So I guess the conclusion is, if you turn you car on, the gas tank pressurizes whether you put the gas cap back on or not and you must depressurize again if you want to put gas in the car.

Anyway, just thought I would share this 'duh' moment. Please correct me if I am incorrect.
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Never had that happen yet, but makes sense. Good to know if I ever have to pull forward to another pump. Thanks
 

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Whoah, not very safe there...

First off, it's a really BAD idea to drive around with your gas cap off and flap open. If the fumes get anywhere near someone who is smoking for example your car could catch on fire. Fuel could spill out and you are also contaminating the air with unburned gas fumes. I read somewhere that one of the reasons why newer cars detect if there's a leak in the gas tank is that lots of people drive around with missing gas caps resulting overall in more air pollution due to gas evaporating. It also goes bad faster too when exposed to air like that.

If you've ever read the manual it says that you must fuel up the Volt after hitting the gas release within about 30 minutes or so. This means that there is an internal valve that shuts closed to help prevent gas fumes from escaping so that's probably your explanation there.
 

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Discussion Starter · #5 ·
First off, it's a really BAD idea to drive around with your gas cap off and flap open. If the fumes get anywhere near someone who is smoking for example your car could catch on fire. Fuel could spill out and you are also contaminating the air with unburned gas fumes. I read somewhere that one of the reasons why newer cars detect if there's a leak in the gas tank is that lots of people drive around with missing gas caps resulting overall in more air pollution due to gas evaporating. It also goes bad faster too when exposed to air like that.

If you've ever read the manual it says that you must fuel up the Volt after hitting the gas release within about 30 minutes or so. This means that there is an internal valve that shuts closed to help prevent gas fumes from escaping so that's probably your explanation there.
Yeah I know I should have put it back on, but I was just going next door and it was early in the morning. The value must also close when you turn the car on because it only took me less than 1 minute to drive next door. As someone stated earlier, it is also good to know in case you pull up to a pump and the pump is not working and you need to pull up to the next pump.
 

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My memory probably is not what it used to be, not that it was ever that good, LOL. I put gas in my Volt so seldom that I almost have to get the owners manual out and figure out how to do it each time, hahaha.
 

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Yes... The Volt's fuel system is pressurized to comply with EPA regulations. (Just like many other new ICE cars today.) The pressure is also held by a secondary flap valve down the filler pipe somewhere. When you start the car the air pump will re-pressurize the fuel system (gas cap or not.) Once the flap valve is closed and the tank is pressurized it's impossible to add fuel. (As you discovered.) Pressing the pressure release button in the driver's door will depressurize the system and let you put gas in the car.

Frankly... I think opening the fuel door should also depressurize the tank.
 
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