Mazda 323/MX-3/626/MX-6/Millenia/Protégé 1990-1998 and Ford Probe 1993-1997

Spark Plug Wires



See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Checking individual plug wire resistance with a digital ohmmeter

At every tune-up/inspection, visually check the spark plug cables for burns cuts, or breaks in the insulation. Check the boots and the nipples on the distributor cap and/or coil. Replace any damaged wiring.

Every 60,000 miles (96,000 Km) or 60 months, the resistance of the wires should be checked with an ohmmeter. Wires with excessive resistance will cause misfiring, and may make the engine difficult to start in damp weather.

To check resistance, use an ohmmeter and attach the leads to each end of the plug wires connector and read the resistance. The reading should not exceed 16 kohms per 3.28 ft. (1 m). Replace any wires that do not meet the specification.


Except Millenia S Models with 2.3L Engines

See Figure 2

Replace the spark plug wires one at a time when installing a new set so there will be no mixup. The longest cable should be replaced first. Make sure that the boot is installed firmly over the spark plug. The wire routing should be exactly the same as the original. Insert the nipple into the tower on the distributor cap and/or coil. Repeat the process for each wire.

Click image to see an enlarged view

Fig. Fig. 2: Remove plug wires by grasping its boot, not the wire, and, while twisting slightly, pull straight upwards

Millenia S Models with 2.3L Engines

The Millenia S uses a 2.3L Miller-cycle supercharged engine which utilizes individual coils for each spark plug. There are no plug wires to inspect or change.