The 'Innovator' models of 1989-90 with the 2.3L engine and all the 'Mach' models with 1990 4.0L engines both came equipped with a distributor less ignition system while all the remaining models used a distributor ignition system. Before disconnecting and reconnecting the distributor cap use a marker to identify each of the spark plug wires by their respective cylinder numbers, then, remove the cap hold down screws and lift the cap vertically so as to not damage the rotor blade and spring. If there isn't enough room, then make truly certain that the plug wires are properly labeled before removing them from the cap. Installation is the reverse and caution is paid to particularly the square alignment locator hold-down screws should be tightened to only 18-23 inch pounds (2.0-2.6 Nm). To replace the rotor begin by unscrewing the distributor cap, after that one pulls up on the rotor in order to separate it from the shaft and the armature, for installation the tricks are conversed, the locating boss of the rotor should fit into the hole on the armature and the rotor should be fully seated onto the shaft. For inspecting the distributor cap, wash inside and outside surfaces with soap water and then by air drier, for checking crack, broken or worn carbon button, carbon tracks, and dirt or corrosion of the terminals of the cap if found disturb replace the cap. For the rotor, wash with soap and water and blow with compressed air to help crack, carbon tracks burns, damage of the blade or spring to replace if any was observed.
