Zippo lighter doesnt lite?

i recently got a used zippo from a friend and worked fine until it ran out of fuel; so i filled it with bbq lighter fluid and doesnt light. i got new flint and sparks great but the fuel doesnt go into the wick. i pulled the wick to expose fresh wick and nothing. i even tried rubbing alcohol, and nail remover. i made sure it was full of fuel,and i even primed the wick with fuel and burns that then goes back out. what could be the problem?