Spark plug wires are a critical link in a vehicle’s electrical system. Responsible for transporting electrical power from a vehicle’s ignition system to its engine spark plugs, spark plug wires need to function properly to ensure normal engine operation. When spark plugs wires fail, a host of engine problems can result.
Rough Engine Idle
The most common symptom of bad spark plug wires is a rough engine idle. Spark plug wires are responsible for transmitting the electrical current from a vehicle’s electrical system to the engine spark plugs, where the electrical current is used to ignite the engine air/fuel mixture. Bad spark plugs wires can inhibit the normal flow of electrical current that reaches a vehicle’s spark plugs, which can cause a rough, erratic engine idle.