Gas nozzle clicking off, gas nozzle, filler tube

QUESTION: Why does the gas nozzle click off when putting gas in the car.  It acts like the tank is full and takes a long time to fill tank.

ANSWER:      There is a little thingy in the nozzle that senses when air starts to back up in the filler tube, and it cuts off the nozzle.  The nozzles used in the old days weren't very sensitive, but modern ones have to be to prevent you from overfilling the tank.  The vapor recovery system in a modern fuel-injected car is designed to recover vapor, not liquid gasoline.  If you fill the tank up completely, ignoring the clicker, you will have so much fuel in the tank that some of it will go into the vapor-recovery canister.  There is no way for the liquid fuel to get out of the canister, so it eventually fills up and overflows into the air inlet, completely screwing up the fuel-metering system and gumming up the throttle body.  Not to mention the fire hazard.

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QUESTION: So if this has happened how do I fix it?  This sounds logical because I was filling up my car and set the pump handle to click off while I was in the car because it was cold and all of a sudden I heard a splashing sound and I saw that there was gas on the ground and the pump finally stopped.  I do have a tendency to try to round off the dollar numbers on the pump so this is possibly what I have done.  I just need to know how to fix it now please.  Thanks

Answer
    I would recommend taking the car to a dealer or a very good mechanic.  Most mechanics don't know how this system works, or what can be done to cure a problem with it.  But first I'd wait and see if you can replicate the problem at your next fillup.  Use a different pump next time.  If it doesn't do the same thing, then the problem is probably in the nozzle.  At that point I would complain to the gas station where the problem occurred and let them know they have a problem with that particular nozzle.  They may have already fixed it.
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