- Idle Air Control (IAC) valve: The IAC valve controls 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 stopped at a light.
- Throttle Position Sensor (TPS): The TPS tells the engine control unit (ECU) what position the throttle is in. If the TPS is faulty, it can send an incorrect signal to the ECU, which can cause the engine to stall.
- Fuel pressure: Low fuel pressure can cause the engine to stall, especially when the engine is under load, such as when the car is accelerating or climbing a hill. A faulty fuel pump, clogged fuel filter, or leaky fuel injector can all cause low fuel pressure.
- Ignition coils: The ignition coils provide the spark that ignites the fuel in the cylinders. If an ignition coil is faulty, it can cause the engine to misfire, which can eventually lead to stalling.
- Vacuum leaks: Vacuum leaks can cause the engine to run lean, which can lead to stalling. A vacuum leak can be caused by a cracked or loose hose, or a faulty gasket.
