- Faulty Idle Air Control (IAC) Valve: The IAC valve regulates the amount of air that enters the engine when the throttle is closed, such as when the car is idling. A faulty IAC valve can cause the engine to stall when it cannot maintain a steady idle.
- Vacuum Leaks: Vacuum leaks can cause the engine to run lean (too much air, not enough fuel) and lead to stalling. Check for any loose or cracked hoses in the vacuum system, especially around the intake manifold and throttle body.
- Fuel Pressure Issues: Low fuel pressure can cause the engine to stall, especially under load or at higher RPMs. Check the fuel pressure using a fuel pressure gauge to see if it meets the vehicle's specifications.
- Faulty Throttle Position Sensor (TPS): The TPS provides information about the throttle plate's position to the engine control unit (ECU). A faulty TPS can send incorrect signals to the ECU, causing the engine to stall.
- Malfunctioning Fuel Pump: A failing fuel pump can cause intermittent fuel delivery, leading to stalling. Check the fuel pump's pressure and flow rate to determine if it's functioning properly.
- Air Filter Clogging: A clogged air filter can restrict airflow into the engine, leading to stalling, especially at low speeds or when accelerating. Check the air filter and replace it if necessary.
- Faulty Crankshaft Position Sensor: The crankshaft position sensor provides information about the crankshaft's position and speed to the ECU. A faulty sensor can cause the ECU to misinterpret engine conditions, leading to stalling.
- Engine Mechanical Issues: In rare cases, stalling can also be caused by mechanical problems such as worn piston rings, damaged valves, or low engine compression. If none of the above solutions address the stalling issue, further diagnostic testing may be necessary to determine the exact cause.
