90' 300CE rough idle/missfire

[DMITRY]

I guess this is another one for Arthur.
Car starts but idles rough and misfires. As soon as I put it in gear it gets rougher and/or dies (turning a steering wheel while in Park or Neutral causes same effect). A new blower motor worked intermittently when problem begun but now not working at all. While engine was running, lifted the hood up, noticed that several continues sparks are going from ignition coil wire to surrounding engine parts.
"Recently" (2 years ago) changed voltage regulator after old one completely warned out. Car is not used much. Basically start it to repark once or twice a week for street cleaning.