What causes the Passat New Lingyu to shake during cold starts?
1 Answers
Passat New Lingyu cold start shaking may be attributed to the following reasons: Low Temperature: The temperature inside the engine is insufficient, and both fuel and lubricating oil are not adequately warmed up. Therefore, during a cold start, more fuel should be injected to meet the power requirements. The larger the spark plug gap, the smaller the ignition energy. At low temperatures, fuel atomization is poor, requiring higher ignition energy. Over prolonged use, the ignition gap of spark plugs tends to widen, leading to reduced ignition energy, which affects performance and causes the car to shake. Inappropriate Air-Fuel Ratio: Inaccurate air-fuel mixture ratio occurs in both open-loop and closed-loop control systems. In vehicles with closed-loop control, the oxygen sensor's minimum operating temperature is 370 degrees Celsius. If the car is just started, the exhaust pipe temperature may not reach 370 degrees Celsius, preventing the oxygen sensor from functioning. In this scenario, the ECU makes incorrect judgments, leading to errors in controlling the air-fuel mixture and ignition timing through actuators, thereby reducing the vehicle's power output and causing shaking. Faulty Coolant Temperature Sensor: The coolant temperature sensor is one of the critical inputs for the ECU to determine the engine's operating condition. If the engine is started at -10 degrees Celsius, the ECU will inject fuel based on a 20-degree Celsius condition, resulting in less fuel being injected and naturally causing shaking.
