What are the symptoms of a faulty ignition wire in a car?
3 Answers
Here are the fault phenomena caused by a faulty ignition wire in a car: 1. Unstable engine operation or shaking: For example, reasons such as poor quality or aging of the high-voltage wire can cause this. 2. Single or multiple cylinder misfires or intermittent faults: For example, individual high-voltage wires with quality issues leading to poor conduction or resistance changes may cause this. 3. Abnormal ignition: The engine may experience weak acceleration, hesitation, or poor acceleration; For example, during use, the conductivity of the high-voltage wire weakens, internal resistance increases, resulting in reduced ignition intensity to the spark plug, weak ignition, and incomplete combustion.
I've been driving this car for over a decade and have encountered issues with ignition wires before. Back then, I distinctly felt the car shaking violently at red lights, with the entire steering wheel vibrating like an overactive massage chair. When accelerating on the highway, there was no power, and the engine sound was intermittent, like someone speaking while being choked. Later, I noticed the fuel consumption skyrocketing - whereas a full tank used to last 500 kilometers, it barely reached 400 before the warning light came on. The most nerve-wracking moment was when it took five or six attempts to start the car on a rainy day, almost making me late to pick up my child from school. Now, whenever I see the engine warning light flash yellow or smell gasoline from the exhaust, I know it's time to check the ignition wires. When these wires age and leak electricity, they severely affect spark plug performance.
Over the years working in the repair shop, I've diagnosed numerous vehicles with ignition wire failures. The most common symptom is the tachometer needle bouncing up and down at idle, like it's on a trampoline. When listening with a stethoscope near the engine cover, you can hear irregular ignition in one cylinder with intermittent clicking sounds. When owners complain about jerky acceleration that feels like riding a horse with bumpy movements, there's an 80% chance it's caused by cylinder misfire due to leaking ignition wires. We typically start by pulling the wires to measure resistance - aged wires can spike above 10,000 ohms, while new ones measure around 5,000-6,000 ohms. In severe cases, you can even see blue-purple electrical sparks at cracked insulation points. Such situations require immediate wire replacement, otherwise it could damage the catalytic converter.
