1. Idle Air Control (IAC) Valve Issue: The IAC valve is responsible for controlling the amount of air that bypasses the throttle plate when the engine is idling. If the IAC valve is faulty or dirty, it can cause the engine to stall when the throttle is closed, such as when the car is idling at a stop light.
2. Throttle Body Issues: A dirty throttle body or a faulty throttle position sensor can also lead to stalling at idle. The throttle body regulates the amount of air entering the engine, and if it's clogged or the sensor is faulty, it can disrupt the air-fuel mixture, causing the engine to stall.
3. Vacuum Leaks: Vacuum leaks can cause a lean air-fuel mixture, leading to stalling. Check for leaks in vacuum hoses, gaskets, or other vacuum-related components.
4. Fuel System Problems: Issues such as a failing fuel pump, clogged fuel filter, or a faulty fuel injector can affect fuel delivery and cause the engine to stall.
5. Electrical Issues: Problems with ignition components like spark plugs, spark plug wires, or the ignition coil can also lead to stalling.
6. Computer (ECU) Issues: If there are any issues with the engine control unit (ECU) that controls various engine parameters, it can cause the engine to stall.
To diagnose the exact cause of the stalling, it's recommended to have the vehicle scanned for trouble codes using an OBD-II scanner. The retrieved codes can point towards the specific components that need to be inspected or replaced to resolve the stalling issue.
