What are the symptoms of excessive carbon deposits on spark plugs?

[DiArabella]

Symptoms of excessive carbon deposits on spark plugs include: 1. Difficulty starting the car, and in severe cases, the car may not start at all. Spark plugs are part of the car's ignition system, and when they are heavily carbonized, the fuel and air mixture in the engine cylinders cannot be ignited normally; 2. Excessive carbon deposits on spark plugs can affect the combustion of fuel and air mixture in the engine cylinders, causing shaking or fluctuating engine speed when idling; 3. Carbon deposits on spark plugs prevent fuel from burning normally, leading to insufficient power, resulting in weak acceleration or slow speed increase; 4. The fuel-air mixture does not burn completely, leading to unburned gases in the exhaust, causing black smoke from the tailpipe and exceeding emission standards; 5. Excessive carbon deposits on spark plugs prevent normal fuel combustion, causing fuel to be consumed too quickly, leading to increased fuel consumption.