Engine Problems

Hello everyone

I changed the timing belt and some other things.
The engine is not really running around now during test drive.
I checked the setting again with fixation flanges, control times are right.
Then I looked at the spark plugs, and I saw
Note that the spark plugs of cylinder 2 and 3 black and
Wet, the others made a good impression deer brown and dry.
I suspect the ignition coils, because the ignition spark does not
I'm right or I'm totally wrong.

Greeting:Hajo