Gas Tank Obstruction? Options

[scout742]

When filling my tank with gas, the gas nozzle clicks off, as if the tank is full. It is not. The nozzle clicks off every 1 to 2 seconds. It takes 15 minutes to fill my tank.

Don't know if it's an obstruction in the "neck" or what.

I have tried a dozen different gas pumps at various stations.

Any guesses ?

Also. I can't remember if there was a metal "valve" just under the gas cap. If so, it isn't there now. Could it have become unattached, fallen in, and is blocking the "neck"?

Thanks!