Ezk is a reference to later model volvo "computerized" ignition systems starting with, I think, 1987. I believe it uses crank sensor instead of hall effect sensor in distriburator for timing signal.

Hope this helps.

Joe

I thought that was the prefix for the ignition control computers on certain Volvo ignitions. EZK-XXX would denote the particular version of ignition system in the car (this example being the "age 21 and older" model).