Fuel System Related:
* Clogged fuel filter: Restricts fuel flow, especially noticeable at idle.
* Low fuel pressure: The fuel pump may be failing or the fuel pressure regulator isn't functioning correctly.
* Dirty fuel injectors: Clogged injectors can't deliver fuel efficiently at low RPMs.
* Vacuum leaks: Leaks in the vacuum lines disrupt fuel delivery and idle control.
Ignition System Related:
* Failing ignition coil(s): Can cause misfires, especially at idle.
* Spark plug issues: Worn, fouled, or damaged spark plugs prevent proper combustion.
* Ignition control module problems: This module controls the ignition system; a faulty one can lead to stalling.
Other Potential Causes:
* Idle air control (IAC) valve: This valve regulates air flow at idle; a dirty or faulty IAC valve can cause stalling.
* Mass airflow sensor (MAF) sensor: A faulty MAF sensor provides incorrect air flow readings to the computer, leading to poor fuel mixture and stalling.
* Throttle position sensor (TPS): A malfunctioning TPS sends inaccurate throttle position data, disrupting the engine's control.
* Crankshaft position sensor (CKP) sensor: This sensor is crucial for ignition timing. A faulty CKP sensor can cause misfires and stalling.
* Alternator issues: A failing alternator might not supply enough power, causing the engine to stall. Check the battery voltage.
* Transmission issues (Automatic): While less likely, transmission problems can sometimes manifest as stalling, particularly if the torque converter is slipping.
* Computer/PCM problems: A faulty powertrain control module (PCM) can cause numerous engine problems, including stalling.
Troubleshooting Steps:
1. Check the basics: Start with the simple things – ensure you have enough fuel and that the battery is properly charged.
2. Check engine codes: Use an OBD-II scanner to retrieve any diagnostic trouble codes (DTCs). These codes can pinpoint the problem area.
3. Visual inspection: Look for any obvious signs of damage, loose connections, or leaks in hoses and vacuum lines.
4. Professional diagnosis: If you're not comfortable working on your vehicle yourself, take it to a qualified mechanic for proper diagnosis and repair.
It's crucial to get this issue diagnosed and fixed quickly. Continuing to drive with a stalling engine can lead to further damage or even a dangerous situation. The information above provides potential causes, but a professional mechanic is best equipped to identify the specific problem.
