I was attempting to troubleshoot my tach problem by looking into the connection for the tach in the ignition system. The Bntleys that I just received states that I should EZK ignition, but when I look where that should be my little box says Bosch. Is EZK a brand name or an acronym. The Bentleys doesn't mention anything about non-EZK in 89 & later models. could I have a holdover from an 88 model before the changes to 89?