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.

[ChristianFitz]

I've experienced several instances of stalling while driving over my decade-long driving career. The most common issue is fuel system problems. Last time on the highway, sudden stalling was caused by a failed fuel pump, and the tow truck driver mentioned this part typically lasts about 80,000 kilometers. Next is spark plug aging, where difficulty starting a cold engine serves as a warning sign—my neighbor's car once broke down midway due to this. Another time, a friend's car stalled directly because of severe throttle body carbon buildup, which was resolved after cleaning. Electrical issues shouldn't be overlooked either; a broken alternator belt can drain the battery completely. The most dangerous was when the power steering failed, and I nearly hit a guardrail. My advice: turn on hazard lights immediately after stalling, pull over smoothly, and never attempt to fix these faults yourself.

[LaEthan]

Engine stalling while driving can range from minor to serious. I believe it's clearest to categorize into three scenarios: Fuel supply issues are the most common, like a clogged fuel filter or a burnt-out fuel pump; Ignition system failures come next, caused by things like ignition coil leakage or spark plug electrode erosion; The most troublesome are control system abnormalities, such as a failed crankshaft position sensor or an ECU crash. Last time, my colleague's car stalled because rodents chewed through the sensor wiring. Turbocharged cars also risk stalling from intake system leaks - a ruptured vacuum hose can cause this. I recommend keeping an OBD scanner in your car - scanning the trouble codes instantly points you toward the issue.

[DeLydia]

I was also scared by sudden stalling during my novice days. I remember that time when the car stalled right after passing a traffic light, and the car behind honked frantically. Later, I learned it might just be the fuel tank running empty—the fuel gauge can sometimes be inaccurate. Or it could be due to adding low-quality fuel causing injector clogging; the mechanic said such fuel contains more gum deposits. For automatic transmission cars, special attention should be paid to valve body sticking in the transmission—strong jerking is a precursor. Another time, I forgot to turn off the headlights, which drained the battery, causing the car to stall at a red light. Later, I developed habits: checking the coolant level monthly, cleaning the throttle body quarterly, and replacing the fuel filter annually. These minor maintenance routines can prevent major issues.