1991 backfiring

I have a 91 Metro and its been driving me crazy with all sorts of problems, for quite a while now. Currently, it'll start and idle, but if I hit the gas it either dies or revs up and backfires. Its gettting gas & sparks and I've checked the timing again and again...anyone have any ideas? I at wits end here....

Thanks a lot.

Sounds like your timing belt slipped a tooth. Might wanna take it off, and replace it while you're at it.