4 more cylinders??

hello together...giant problem:was on Monday inner wash road,and one km later my big one started to stutter and spit out of the exhaust.thought right at the distributor cap etc...which could have come in many times water,as well as always.Then suddenly he ran quite normal again and after a few km again..so distribute out and first two new fingers and tight rings in...caps cleaned and the connexion a little guttered.Everything again together and look there, now he just runs away...
all stillma out and the vert.kappeln again looked closely and could not notice anything that goes there somewhere the sparken flutes.
all candles also get a spark(however)
but bein pulling off the single plug was no difference from the motor run to hear at the 6 u 7 cylinder!?beite have a spark

Now to you... you have to help me...
Does the vert.kappen???
Reverberous?
but shows nothing in the error memory!
and all cylinders between 11 and 13 bar compression(at 320000km yet good or)

Please help me ...you guys have had this before
mfg Mario