What Causes a Car to Stall Automatically?
2 Answers
The reasons for a car stalling automatically include: 1. Vacuum leakage in the intake manifold; 2. Unstable idle caused by improper idle adjustment, dirty throttle body, or malfunctioning idle control system; 3. Unstable fuel pressure due to excessive wear or poor contact of the electric fuel pump brushes, or clogged fuel pump filter; 4. Blocked or leaking EGR valve; 5. Malfunctioning fuel pump relay, EFI relay, or ignition relay; 6. Poor contact in the fuel pump drive circuit or injector drive circuit; 7. Issues in the ignition system, such as weak high-voltage spark, worn spark plugs, incorrect ignition timing, poor contact in the ignition coil, inter-turn short circuit in the coil when hot leading to no or weak high-voltage spark, poor contact in low-voltage circuits, intermittent grounding due to damaged insulation, or poor grounding.
Car stalling is really annoying. After years of hands-on experience in the automotive field, I've summarized several common causes: Fuel system issues are the most frequent, such as an aging fuel pump failing to deliver fuel or a clogged filter leading to insufficient supply; ignition system failures like spark plug carbon buildup or coil damage can cause the engine to stall when it fails to ignite; electronic component malfunctions, such as a faulty crankshaft position sensor or engine control unit, can disrupt the computer-controlled fuel cutoff; restricted air intake due to a dirty throttle body or clogged air filter can make the engine run unsteadily; and then there's voltage problems, like a weak battery or alternator failure causing a sudden power drop and stalling at idle. Regular maintenance and periodic checks of these components while driving can help reduce unexpected breakdowns.
