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.

Begin this procedure by visually checking the spark plug wires while the engine is running. In a darkened garage with ventilation, start the engine and observe each plug wire for arcing or sparks at damaged areas. If arcing is noticed, obtain new wires and check the distributor cap and rotor after allowing the engine to cool. Disconnect the negative battery cable and remove the distributor cap by releasing the holddown latches. Inspect the cap for cracks and corrosion on the contacts, removing deposits with a file if necessary. Examine the rotor for cracks, burning, and carbon tracks, replacing it if needed. Apply silicone lubricant to the contact inside the cap before reinstalling the cap and rotor. If the cap needs replacement, leave it off with the wires still connected. If the spark plug wires need replacement, obtain a new set along with a new cap and rotor. Check each wire individually, inspecting for corrosion, crimping the metal connector if necessary, and cleaning the entire length of the wire. Bend the wires to ensure flexibility. Check the wires at the distributor cap, reinstalling them securely. If the wires, cap, and rotor are in good condition, reconnect them at the distributor and battery. If new wires are required, obtain them along with a new cap and rotor. If a new cap is being installed on a coil-in-cap distributor, transfer the coil and cover from the old cap to the new one. Attach the coil to the new cap with a new seal and lubricate it. Attach the rotor to the distributor, ensuring proper installation of the carbon brush in the cap. Replace the wires one at a time, maintaining the correct firing order. Reattach the cap to the distributor and reconnect all wires and the battery cable.

The spark plug wires should be checked at the recommended intervals or whenever new spark plugs are installed.