Ignition miss

Six months ago the engine quit, a local garage replaced the distributor. The truck performed poorly after that and steadily got worse. After some checking I found the single lead wire near the distributor unplugged. This wire is to be unplugged when setting the timing. When I plugged the wire back in a miss developed. When unplugged the miss goes away. More checking found #5 cylinder was the one affected. Replaced cap, rotor, wires, and plugs. No help. There is no spark from the cap to the plug at #5 cylinder when the single lead wire is connected. I checked the compression and valve operation, all is okay. I was told the computer may be bad.
Cheap enough so I replaced it, no help. Also was told the CPS could be bad, this engine gets its signal from the ign. Module. What's next?