engine start

Need sum advice 82 cutlass v8 starts right up.give it gas backfires or pops and will shut off but only shuts off if it’s n gear! it can idle all day rev it up whatever as long as it’s in park! You take it out drive like 3 min or hit tha gas hard it pops! Or backfires and dies put it in Park...

Was wondering if any of you could share any experiences you've had with "barn finds" or cars that have sat for a long time that cranked over and fired up on the first try? I have a vehicle that hasn't run in about five years. I'm nervous about trying to crank it over. Any experiences and advice...