Everytime i fill up my car, if i stick the gas pump filler or whatever it is called all the way in it overflows after 3 gallons. And if i dont put it all the way in it will fill up but then overflows from not shuting off soon enough. It happenes at every gass station. I have tried 10 15 different pumps. Any one have any clue what is wrong????

 

Dude, that's a stumper, def a very weird problem. I've always wondered what triggers the shutoff on gas pumps. If you knew that you might be able to go from there.

 

really need some help any ideas

 

I belive its the gas hittign the metal and causing a back up

 

See that would be the obvious thing and I've never been able to think of anything other then that. If that's the case then your gas must not be going in right or something like that. Have you tried going those 3 or so gallons, waiting a little bit, then trying again?

 

This is what I found
When your gas gauge reads empty, your tank is filled with air instead of fuel. As you add fuel, the air must move out of the tank to make way for the gas. Next time you fill your car at the gas station, take a look at the pump nozzle. You will find a hole about a half inch from the end of the nozzle. This hole is connected to a small pipe that travels through the nozzle to the handle.

When you fill your gas tank, some of the displaced air flows through the hole in the nozzle into the pipe. When the tank is full, the hole will be below the gasoline level and no air will pass through the pipe. A mechanical switch inside the nozzle detects when the flow of air stops and shuts off the gas.

You may have noticed that, after the pump shuts off, you can get more gas in your tank by pulling the nozzle out of the tank a bit. This is because you’re moving the position of the hole relative to the gas level and allowing the mechanical switch to reopen.

 

your e-vac system isn't working..no where for the air to go except back out the filler..

 

vfast is right on about this. the vent line from the gas tank must be restricted somewhere for it not to let the air of of the tank as the gas goes in. check out this line all the way up to the cannister in the engine compartment and look for a kink or blockage in it.

 

is that the line that comes out on the bottom of the back bumper?

 

don't think so, that line just drains the spillage from the fill pipe area, the vent line is off the top of the tank and runs up to the evaporative cannister in the engine compartment where the engine vacuum sucks out the fumes that collect in the tank after the car has been sitting. there should be 3 lines from the tank toward the engine, one is fuel from the pump to the engine, another is the excess fuel return back to the tank, and the third line is the tank vent.