fuel prob i think

I got an 88 LX 4 cyl 5 speed just put a new battery in it. When i go up hill it sputters out and dies. I just learned before I got bought the car someone put a marble in the gas tank as a practical joke. real cute huh. as soon as i get on flat land it starts right up but it won't make it up even the smaller hills. There's supposed to be a new fuel pump on the car too. This cars been nothing but probs since i got it so hopefully this will be it for a while.:banghead:

scratch that it's not when i'm just going up hills
it'll sputter out when i just sit there and rev it and there's a little hesitation too