What Causes a Car to Stall During Normal Driving?

[Cassidy]

Here are the specific reasons why a car may stall during normal driving: 1. During normal engine operation, the fuel pump draws fuel from the tank, which passes through the filter into the distribution lines and is then sprayed by the injectors to form an air-fuel mixture. In this process, the fuel pump and injectors are prone to failure, followed by filter and fuel line blockages. Focus on inspecting these two areas. If necessary, clean the fuel lines. To reduce the occurrence of such issues, always refuel at reputable gas stations with the correct grade of gasoline and ensure timely refueling, avoiding letting the fuel level drop below the red line. 2. Throttle body blockage. Generally, mechanics will consider cleaning the throttle body. However, if frequent cleaning of the throttle body does not fully resolve the stalling issue, it is usually a sign of a fault. Also, check the vacuum pump to ensure normal air intake. 3. Abnormal spark plug ignition. Replace spark plugs according to their service life. In a gasoline engine, the combustible mixture is ignited by the spark plug near the top dead center of compression. Therefore, when a spark plug fails, it naturally causes the vehicle to stall. Typically, replacing the spark plug completely resolves the issue, but temporary fixes like cleaning the electrodes or adjusting the central electrode length can be used in emergencies. Additionally, insufficient battery voltage, leakage, faulty ignition coils, or wiring issues can lead to poor ignition or stalling. 4. Sensor failure causing ECU protective fuel cut-off. Check whether all sensors and actuators are functioning properly. Key sensors include the throttle position sensor, oxygen sensor, crankshaft position sensor, etc.