I have an 81 Concord. 258 auto air. At Idle the car gives off a poping sound through the carb. If I pull number 6 wire the poping goes stops. If I put the wire back on and rev the engine the pop turns into a violent bang through the carb. I have changed plugs wire cap and rotor. Adjusted timing. Compression is 145-150 across all cylinders. It appears to be timing but I can't figure out whats left. no matter where I put the distributor the pop is present. With all 6 wires on the engine will idle. As soon as you pop it in to gear the engine bangs and stalls. If I remove #6 wire I can put the car in gear and drive it. Any Idea's. I am stripping the car but want to make sure the engine runs well before pulling.