OK...I know it's not an F series, but where else am I to turn? Maybe some pickups have the same problem.

I picked up this '92 E150 cargo van, and when I go to gas it up, it kicks off the pump at less than 1/2 a tank full. If I stand there forever I can get 5/8 of a tank tops! I can hear the gas rushing up the filler pipe till it kicks the pump off. Listening some more, I can hear gurgling...then it stops, and I can get a little more in. I have to repeat this over and over and it takes a long time. Got any ideas what the problem could be?

Thanks.