Timing problems 1990 chevy van



when i turn my distributer cap clockwise, it idols and runs fine, but when i give it fuel it back fires and seems to be getting to much gas. now when i turn it counter clockwise, it seems good but it wont idol, it stalls, and anywhere in the middle it sounds like a deisel engine.( like crap) can someone give me any ideas please??


Set the timing properly with a timing light. Then look for the “real” problem.
I suspect a valve timing issue.