my '97 bonneville has been stalling lately and it seems to only happen when my gas gets down to 1/4 tank or less, usually upon initial acceleration. i had this problem once before, and i found a hole in the top of my charcoal canister. i fixed it, and that solved my problem. 2 months later i am having the same problem but my canister appears to be in good condition. I'm thinking the problem is with my fuel lines, or the condition of my fuel tank, or fuel pump. When it stalls, it almost feels like there's a vacuum leak, but all my vacuum lines are in excellent condition. the only vacuum line i can't completely see, is the one that goes from the canister to the gas tank.