When i am trying to put a full tank of gas it stops pumping when it's not full

SOURCE: Hyundai Accent 2003 - gas pump clicks off when tank isn't full.

possible cause could be evap canister full of gas causing back up

SOURCE: Can not pumb Gas into Hyundai 2001 accent

Try moving the handle in a different position, or don't put the nozzel all the way in. The vent tube could be clogged.

SOURCE: gas gauge reads empty but tank acts like it's full

I also have a 04 with a 1.8L. same problem. I took the fuel regulator off. It is a black box behind the rear tire under car. It only has 2 bolts to take off. After that there is a couple of vent hoses from the tank going to this box. Unplug them and 1 electrical connection. The electrical connection and one vent is connected to a T connection on the box that you can unplug by twisting on the T. Take that T off and look inside where you unplugged the hose on this T. There is a spring and a little plunger inside this tube. The plunger gets stuck. I took a little screw driver and some PB blaster and worked that plunger back and forth a couple dozen times and it unfroze. Put it back together gassed up just fine. I did not look but I was told regulator can be replaced for 200$. But a can of blaster is cheaper.

SOURCE: Unable to put gas into the tank.

There is a filter on the tank vent that is plugged. It is not letting the air escape from the tank during fillup causing positive pressure which will will shut off the gas pump. I don't know where it is on your model but some are under the back behind the fuel tank. It is usually a 6" square plastic box with a hose on it and louvers on the sides.

SOURCE: Filling my gas tank the pump keeps shutting off

Its a fact the pump will kick off on some makes especially trucks. here is a hint. When filling up insert the nozzle fully and then pull it back one inch. This way it will not stop or splash back at you which some pumps do