Just started to notice at 4,000 to 6,000 rpm there are places the motor makes a hicup. At 4000 5000 and 6,000 almost at those marks on tach. I have new plugs but that is it.. 76,000 miles 1996 C 36. The things that have NOT been replaced are o2,MAS, coils, coil ends, wires. Got any clue what to look for? I have a Powerchip in ECU. KN filter. Of a side note.. to start the car is weird. Sometimes it fires right up.. then sometimes I have to turn it for 7 seconds plus.. when it fires it spits a small amount of black smoke that goes away after 1 or 2 seconds. When I have this long start problem the car has a cough to it and then slowly will idle.

Did you notice the symptoms before the new plugs were installed? If you hadn't mentioned that, my response would have been to check them anyway. You may have the wrong plugs or they could be gapped wrong.

Steve

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'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7

Along w/Steve on the plugs... change the coil connectors under each coil ..
Not only are they known to cause igniton faults,but the ECU on those waste spark systems shuts down the injector when an ignition skip is detected , compounding the symptom...
They are cheap and that is one of the few recommended 'just change them' parts..
Remember , on this type of ignition system, the spark has to travel through these connectors to reach EACH of the 6 combustion chambers b/c each coil feeds 2 plugs [ they are wired in Series]
So, the skip can be more pronounced under load...
[ usually resulting in slight miss at idle , also]
The fault is not usually the resistor in the boot, but rather the spring that tension connects to the plug tip.. My opion is that it is a weak connection from design and fatiques early due to trapped heat. Whereas the other 3 have a solid Snap connector that seems to hold up well and air circulation is better than the the coil on top three..

I want to make sure we are talking the same thing.. the MB dealership wanted to sell me the rubber end that on the far coil towards the front of the car comes off the top of the coil and points to the grill. This is about 2" max in size and he told me I needed a special tool to install into the wire.. on the other hand I see a long black "tube" that runs below the coil itself and attaches to the spark plug on every other cylinder. It looks like the reddish ones that are attached to the spark plugs except it is black and made of rubber vs. ceramic.. also, so I don't screw it up, what is the best method of removal from the coil, just pull? Sure enough I will do the wrong thing and have to tow the car in etc.. Thanks

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Correct to both ???s...