hesitation

ive been trying to get the '81 thats in my profile running good for a while now. it idles fine. but when i give it gas, it wants to die out, almost as if it was flooding or still cold. it was running ok enough to drive like a month ago. now it wants to die when i give it gas, then if i can get it going in first gear, it hesitates and jumps, almost as if it was out of gas. any ideas?