GMC 19170839 Wire Kit,Spark Plug

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 or coil. Replace any damaged wiring. Every 50,000 miles (80,000 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, remove the distributor cap, leaving the wires in place. Connect one lead of an ohmmeter to an electrode within the cap; connect the other lead to the corresponding spark plug terminal (remove it from the spark plug for this test). Replace any wire that shows a resistance over 30,000 ohms. The following chart gives resistance values as a function of length. Generally speaking, however, the resistance figure shown is considered to be the outer limit of acceptability; so, if the wire approaches the maximum, you should replace it to prevent trouble in the future. Up to 15 in. (38 cm): 3,000-10,000 ohms. 15-25 in. (38-63 cm): 4,000-15,000 ohms. 25-35 in. (63-89 cm): 6,000-20,000 ohms. Over 35 in. (89 cm): 25,000 ohms. It should be remembered that resistance is also a function of length; the longer the wire, the greater the resistance. Thus, if the wires on your vehicle are longer than the factory originals, resistance will be higher, quite possibly outside these limits. When installing new wires, replace them one at a time to avoid mixing them up. Start by replacing the longest one first. Install the boot firmly over the spark plug. Route the wire over the same path as the original. Insert the nipple firmly onto the tower on the distributor cap, then install the cap cover and latches to secure the wires.

Clean the wire with a rag, removing dirt and grease, and inspect for burns, cracks, or other damage. Bend the wire in multiple places to check its flexibility.

Each wire should be inspected for corrosion, and the metal connector should be crimped if necessary. The entire length of the wire should be cleaned.