HI folks. I have a 1997 chevy blazer with the 4.3 with 206k niles. i purchased it running, but running poorly. engine light on. I replaced the plugs and wires and it made a positive difference. But engine light still on. Everyone kept saying its miss firing. Sometimes vehicle wont even allow any power use to show when turning key, only if the gas needle goes upside down. usually trying the key several times would get it going. sometimes while driving the engine would shut off. But then id give it some gas while flying down the road and it would fire back up. One day while coming home the engine acted as if half the power disappeared. So next day i try to start it and its just sputtering and sounding awful. Can barely climb a hill! So i let it sit then try again and cant get anything except dead rotation. Talked to some people and was suggested new distributor so i put one entire distributor assembly in. no change. Engine has great compression. I lost on why it wont work. any ideas?

 

The sputter when you let the key come back might be a clue, check to see if the ignition coil has power when the key is in the on and then in the crank position, if it looses any power in either position replace the ignition switch and follow the instructions on the proper way to set it up.