The Engine is 111.961 Chasis 202.022 . Yes its C220 1994 model. I have pulled the car apart to access the Ignition Coil # 0001500480 & Its harness # 2025403809 . The harness had live wire contact due to disintegration insulation.

I want to firstly rule out the Spark Plug wire, then the ignition coils. I had already repaired the coil harness (i think? I need a detailed schematic on this) and replaced with 4 new Spark Plugs. When I put all this together yesterday, the car just shook. May be 2 coils not firing? I dont have a diagnostic tool to show, so now i have pull everything apart again, Wanting to test them individually.

The symptom now is different from before I pull apart the 1st time. Initially was no power but now there is power but it shakes violently when stationery.