The purpose of your vehicle's spark plugs is to ignite the fuel and air available in the combustion chamber. They do this because of a signal received from the computer module or distributor cap.
If the ignition cable, or spark plug wire, carrying this signal fails, the operation of the engine becomes mistimed and under-powered. One or more cylinders will misfire or weaken. Another result of the fuel and air not combusting completely is a buildup of gases and residue in your injectors or cylinders.
Symptoms of a Bad or Failing Ignition Cable:
1. The decrease in power, acceleration, and fuel efficiency:
One of the most common symptoms of an issue with the Spark Plug is engine performance problems. The Spark Plug carries the spark from the coil and distributor to the spark plugs so that engine combustion can occur. If there is any issue with the spark plug wires the engine spark can be disturbed, which can result in engine performance issues such as misfires, a reduction in power and acceleration, as well as a reduction in fuel efficiency. In severe cases, bad cables may even result in engine stalling.
2. Check Engine Light comes on:
Another symptom of a potential issue with the Spark Plug is an illuminated Check Engine Light. Faulty cables can lead to engine misfires as well as excessively rich air-fuel ratio, both of which can set off the Check Engine Light if detected by the computer. A Check Engine Light can also be set off by a number of other performance issues, so having the computer scanned for trouble codes is highly recommended.
Replacing the Spark Plug Wires:
Step 1: Disconnect the battery. Disconnect the negative battery cable to cut power to the Spark Plug.
Step 2: Locate the Spark Plug. The cables will be routed from the spark plugs on the top of the cylinders to the distributor cap or module that powers them.
Step 3: Replace the cables. One by one, remove and replace the spark plug wires. To remove an old cable, pull directly upward on the boot of the cable on the spark plug end, and then pull upward on the boot connected to the distributor cap or module. Be sure to only pull on the boot; DO NOT pull on the cable itself. Make sure that the length of the cable you disconnected is the same as the length of the new cable. Extra wire is unnecessary and your engine may not have room to compensate
Step 4: Reconnect the battery. Reattach the negative battery cable to the terminal to restore power.