How can I get my zippo to light more reliably?

My flint is working because I see plenty of sparks and my zippo is full of lighter fluid. It will work for about an hour after I refill it, but then stop and it will burn well if I light it with another source or dampen the wick with lighter fluid. But I can't get it to light a few hours after refilling, or if I do its only after about 10 tries. I get the sense that the wick isn't getting any fuel but I already tried trimming and pulling out the wick. Please Help, Thanks!