How is the ignition timing set on a 1987 190E 2.3-16? I have a Haynes manual, but this only tells you the procedure for the 8-valve engine. The plug that the manual tells you to remove to set the timing is diffent in my car. Also, the box that the wires are connected to is much bigger in my car. There is one wire that can be removed, but you can't turn the car on with that wire removed so obviously that isn't the right wire to unplug. Basically all I am wondering is which wire is supposed to be unplugged to set the timing? The actual procedure I am familiar with.