- Idle Air Control Valve (IACV): The IACV regulates the amount of air that enters the engine at idle. If it is faulty or dirty, it can cause the engine to idle roughly or stall. Clean the IACV and check for proper operation.
- Throttle Position Sensor (TPS): The TPS sends a signal to the engine's computer (PCM) about the position of the throttle. If it is faulty or misadjusted, it can cause the PCM to provide incorrect fuel and air mixtures, resulting in rough idling. Check the TPS for proper adjustment and operation.
- Vacuum Leaks: A vacuum leak can cause the engine to run lean, which can lead to rough idling. Check all vacuum lines and connections for leaks, especially around the intake manifold and throttle body.
- Faulty Oxygen Sensor: The oxygen sensor monitors the oxygen content in the exhaust gas and provides feedback to the PCM to adjust the air/fuel mixture. If it is faulty or slow to respond, it can cause the PCM to provide incorrect fuel and air mixtures, resulting in rough idling. Check the oxygen sensor for proper operation and replace it if necessary.
- Fuel Pressure: Low fuel pressure can cause the engine to run lean and idle roughly. Check the fuel pressure and make sure it is within the manufacturer's specifications.
- MAF Sensor: A dirty or faulty mass airflow sensor can cause the engine to run rich or lean due to incorrect air flow measurements. Try cleaning the sensor and verify its signal readings are accurate.
Remember that identifying and fixing the underlying cause of the idling problem is important to ensure the proper functioning of your vehicle. If you are not confident in your ability to troubleshoot and repair the issue yourself, it is recommended to take your vehicle to a qualified mechanic.
