New to the site, hello to all. Here i go, i got a 2000 A4 1.8t 5 spd manual.

got to the gas station car running perfect like always, fill the tank up, tried to start and it did not. parked it in a safe place. wouldn't start. took a ride home. called a friend know a little more than i about cars. told me his 2002 vw golf, had a similar problem. everytime he went to get gas, his car would not start and found how to start it, but not the problem. he push the gas pedal all the way in and hit the start, car start after 5 second or so, like starvin for gas and then back to normal. till he gets gas again. well i tried that on my A4 and sure enough it started the same way. my friend even tried to put gas with the car on and it shuts down. my question is there a sensor of some type for ventilation pressure on tank? or what's going on? Is it that popular first person i asked it had happen too. where do i start ?