What Causes the Engine to Stall After Starting?
3 Answers
The reasons for the engine stalling after starting are as follows: 1. Triggered Anti-Theft System: The anti-theft system is activated, locking the engine, which allows the engine to start but not run. Releasing the key causes it to stall, and the anti-theft light illuminates. 2. Ignition Switch Failure: During startup, the ignition line has power, but releasing the key cuts off the power, causing sudden stalling. This is usually due to poor contact of internal contacts in the ignition switch, often accompanied by issues like the dashboard battery light, oil light, and engine fault light not illuminating. Some may experience intermittent failures such as no AC heating, headlights not working, or power windows malfunctioning before the problem occurs. 3. Damaged Ignition Module or Faulty Ignition Reference Signal Line to the Engine Computer. 4. Low Fuel System Pressure: Issues like low fuel pump pressure, fuel line leaks, insufficient power supply current, or a faulty fuel pressure regulator. When fuel system pressure is too low, the normal injection time delivers too little fuel, making the mixture unable to ignite under compression. However, during startup, the extended injection time due to the startup program compensates, allowing the engine to start despite low pressure. Once running normally, it stalls due to insufficient fuel. Additionally, if the fuel pump fails to deliver fuel, the engine may start in the first few attempts but stalls immediately after.
When my car had this issue, I was initially very nervous. The engine would start and then suddenly die, as if it had lost power. There are several possible reasons: First, there could be a problem with the fuel system, such as an aging fuel pump causing unstable fuel supply or clogged fuel injectors, leading to insufficient air-fuel mixture. Second, the ignition system might be faulty—spark plugs fouled with carbon deposits failing to ignite or damaged ignition coils causing the engine to stall when the spark stops. Third, sensor malfunctions, like a faulty mass airflow sensor or crankshaft position sensor, can send incorrect signals to the ECU, triggering a shutdown. A stuck idle control valve is also common, cutting off the engine if there isn't enough air to maintain idle. My advice: don't wait. Quickly visit a professional repair shop to check fuel pressure and electrical circuits to avoid long-term damage to the engine's core components.
As someone with car repair experience, I've handled many similar cases. An engine stalling after starting mostly stems from three major systems: fuel, ignition, or control components. On the fuel side, a weak fuel pump or clogged filter cuts off fuel supply. Ignition defects like excessive spark plug gaps or aging high-voltage wires prevent proper sparking. Control system issues such as faulty intake sensors sending incorrect signals can cause the ECU to mistakenly shut down the engine. Carbon buildup in the idle control valve may lead to insufficient power at idle. Aging batteries can also cause this issue - they might hold up during startup but voltage drops during operation lead to stalling. For diagnosis, start by checking trouble codes with an OBD tool, then measure system voltage and spark intensity. Never ignore this issue, as prolonged neglect could damage the catalytic converter or cause more severe failures. Regular inspections can prevent most problems, saving money and ensuring peace of mind.
