Ford Fiesta Fuel Filler Neck anti syphon Device?

I thought the anti-syphon was just a plate across the filler throat that make it hard to get a piece of tubing into the tank - That's what the American Ford's have. If so, you can't really hurt it. But, there is a small runner tubing that goes from the top of the gas tank to just inside the gas cap, to let the air out of the tank while the gas goes in. Those hoses do kink & twist & quit venting, & that will cause gas to quit pumping, unless you go very s l o w l y . If you think the vent tube could be your problem, crawl under & see if you can see it running along the larger filler neck.