Started running bad: maybe plug wire??

[ky_kid]

So my truck has been running rough recently and here's the story... One day I'm driving and it dies while moving. When I stop it will fire but won't hardly run unless I give it throttle and then it's rough and blowing black smoke. When I get under the hood the plug wires came off their support and were laying on the exhaust. I hung them back up and it ran ok but not like it should. Since then it has less power, using more gas, and when revved in park blows soot, moisture, and black smoke.

I replaced the plugs, could I have ruined a plug wire? Am I running on 7 cylinders? The wires don't look burnt or melted...