I recently purchased a 1993 300E 3.2 L model. The car is mint 117K miles one owner all records. The valve cover was very ugly so I removed it and sandblasted it and had it powder coated. Now rebember powder coating is applied with an electromagnetic charged powder and then oven baked over 300 degrees heat. Replaced all the rubber seals before reinstallation . Next after reinstallation tried restarting and battery was completely dead. Next( bad idea) charged it with my little beemer. The "surge relay"15 amp fuse never had a problem so for now lets say the fuse is good so the relay is good so the engine computer "is good"!!!.Next the engine started but missing in idle strong fart smell and catalytic got fireworks red. Shot down.Check for any intake leaks.None.Next moved around all coils and spark plug terminals and restarted engine. Now missing in idle running a little better Cat fine no smell but not running good.Next under advise and after doing a little research removed the valve cover to check for the position of the "three curved metal contacts" that feed ground?? to the valve cover I guess and so to each of the coils??And no body could tell me on this side of the border,This is my only logical answer to the reason for this metal brakets. Now it wouln't start. After trying restart it backed fired several times and a small cloud of white smoke came from the driver's side front engine section around the cam solenoid,cam sensor etc.. area couln't tell from inside the car. Under advise replaced the crank sensor and now it would turn and no spark so it is getting better!!?? Can the jump or lets say the charge from the other car have damaged the computer without damaging first the fuse and /or surge protection relay. ??What is the proper position for the metal contacts under the valve cover.??What other component or components emit signals to the computer so it can then send current to the coils.Sorry for the length of the thread but I wouldnt want nobody else to live this experience again. Mercedes Mercedes after all is a woman's name. I hope a lady has the aswer. No offense I love my wife and have a wonderful daugther. Joe Bart Thanks