Cold start with only 7 cylinders and restless running

Hey, guys.

I rarely get in touch here in the forum to ask anything, but that's simply because I usually get my answers about the search function and the reading of the previous answers. (TOI TOI TOI)

But now to my real problem:
Recently, it is more common that when I start the engine, it probably only runs on 7 cylinders. Of course, he'll be a little shivering.

The restless run usually takes place after a few meters. It is only now possible that the engine only takes about a year. after 3-4 KM runs round again. (It certainly isn't that great)

I've read a lot of things. But I don't really know where to start. On the one hand, it can be because it is quite humid in the morning and therefore the ignition distribution may be. The Commission has a dropout. It can also be a fuse cable that can be used for the ignition. a marten bite (which I have not yet found) or of course other causes such as individual spark plugs ...

I think those who have had similar experiences may give me some tips on what might be the most likely cause of such a problem.

PS: What I would like to mention:
It may also depend on the sometimes falling or falling. Fluctuating speed in the range 1000 - 2000 revolutions combined. This usually occurs when taking gas away. However, it runs quite tough during this time. he then also does not take the gas clean and the drivage is then really modest.

Oder was meint Ihr ?

With my other vehicle I had that once, but this had been given again by a "reset" of the engine control unit.

Merci already
Greetings Ray