During every tune-up/inspection, visually check the spark plug cables for fluid contamination, burns, chaffing, cuts, or breaks in the insulation. Check the boots and the nipples on the ignition coil or distributor, if equipped. Replace any damaged wiring.
Every 60,000 miles (96,000 km) or 48 months, the resistance of the wires should be checked with an ohmmeter. Wires with excessive resistance will cause misfiring, and may cause the engine to be difficult to start in damp weather. Ignition wire resistance should not be greater than 25 kilohms.
To check resistance, remove the spark plug wire from the plug and ignition coil or distributor. Using an ohmmeter, measure the resistance of the wire by placing one lead of the ohmmeter at one end of the ignition wire, and the other ohmmeter lead at the other end of the ignition wire.
If the measured resistance is above the specifications, the ignition wire must be replaced.
REMOVAL & INSTALLATION
The spark plug wires must be routed and connected properly. If the wires must be completely disconnected from the spark plugs and from the distributor cap or ignition coil at the same time, label the wires to assure proper reconnection.
When installing a new set of spark plug wires, replace the wires one at a time to avoid mixing them up. Start by replacing the longest cable first. Twist the boot of the spark plug wire 1 / 2 turn in each direction before pulling it off. Install the boot firmly over the spark plug. Route the wire exactly the same as the original. Insert the nipple firmly onto the tower of the distributor cap, if equipped. Use a silicone dielectric compound on the spark plug wire boots and distributor cap connectors prior to installation.