Mercedes Benz C200 Elegance 1998 .The car works on plugs 2 and 3.There is no spark on plug 4.Plug 1 sparks when starting but immediately looses spark.I replaced the coil pack but the problem persists.

SOURCE: mercedes c200 elegance 1996 model mis-firing on cylinders 1-4

I beleive your firing order is 1 3 4 2. 1 and 4 are companion cylinders-meaning the piston is up or down at the same time i.e. compression and exhaust stroke both pistons are up and even on the exhaust stroke the ignition fires in order to burn unburnt fuel/ h ve you checked your trigger. There is a good coil testing tool that is placed over the coil and has a magnetic pickup that allows you to see if the coil is being triggered-just because you have power doesn't mean that you will have spark. I would replace your ignition wires and look at your wiring harness very carefully- if it is very brittle and you see bare wires exposed that is your most likley problem because the trigger is working for 1 and 3 and has the crank senser input for all for spark plugs and the cam senser is used for ignition advance and your fuel injection system. try wiggling your harness and see if your coils start to work. wireharnesses are a major problem on mercedes benz vehicles of that era. I hope I have been helpful