Bad engine running

[Coupe]

Hello, may you can help me. Since a few days, my MM is bad running after start cool engine. Means, the engine runs only with 7 cylinders. After a short time, everything is perfect. I have no DTC's
What will it be?

[Curless]

Hello, may you can help me. Since a few days, my MM is bad running after start cool engine. Means, the engine runs only with 7 cylinders. After a short time, everything is perfect. I have no DTC's
What will it be?


I would look for which cylinder it is. If you pull your coils out, keep track of which cylinder they belong to. One may look different than the others....it may have carbon tracking on the boot.

[fastblackmerc]

I would look for which cylinder it is. If you pull your coils out, keep track of which cylinder they belong to. One may look different than the others....it may have carbon tracking on the boot.

Pull the spark plugs also, the affected one should look different than the others.

[Coupe]

forgot to write, the sparks are replaced and the old one was in the same good condition

[Curless]

Can you watch the cylinders on a scanner? You will find missfire counts on the one that is affected. Take that coil and switch it out with another one and see if the missfire moves. If it does, there is your issue!

[Coupe]

i have a IDS/VCM, but i can´t work with it, but read the DTC´s! :-)