Hi,
I have a 98 16 16v Vectra that seems to be misfiring and rough idling. First I changed the spark plugs and it cured the problem for a short while. I noticed that the plug cyinder 3 had more deposits (dry black), compared to the other 3 which were brand new as you would expect. Next I replaced the coil pack and the plugs, which again, cured the problem. the plug in cylinder 3 is again more discoluored than the others. I've had a few suggestions that it may be a worn cam lobe.
Any suggetions or advice would be much appreciated before I have to cross the local garage's palms wich wads of notes!
Cheers