Fuel System:
* Fuel pump failure: A failing fuel pump can't deliver enough fuel to the engine, leading to stalling. This is a common issue in older cars.
* Fuel filter clog: A clogged fuel filter restricts fuel flow, resulting in similar symptoms to a failing fuel pump.
* Fuel pressure regulator problems: A malfunctioning regulator can cause erratic fuel pressure, leading to stalling.
* Clogged fuel injectors: Dirty injectors can prevent proper fuel delivery to the cylinders.
Ignition System:
* Crankshaft Position Sensor (CKP) failure: This sensor tells the engine's computer where the crankshaft is, crucial for timing the ignition. A faulty CKP will cause the engine to die.
* Cam Position Sensor (CMP) failure: Similar to the CKP, a bad CMP sensor disrupts ignition timing.
* Ignition coil problems: A failing ignition coil can prevent one or more cylinders from firing, potentially leading to a stall.
* Distributor cap and rotor (if applicable): Wear and tear can cause poor spark delivery. (Less likely in a 2002, but some models might have this)
* Ignition switch malfunction: A faulty ignition switch can interrupt the power supply to the ignition system.
Electrical System:
* Alternator failure: The alternator charges the battery. If it fails, the battery will drain, eventually causing the engine to stall.
* Battery problems: A weak or failing battery can't supply enough power to the engine, causing it to die.
* Wiring issues: Corroded, damaged, or loose wiring can interrupt power to critical components.
Engine Issues:
* Mass Airflow Sensor (MAF) problems: A faulty MAF sensor provides inaccurate information about the amount of air entering the engine, leading to poor fuel mixture and stalling.
* Throttle Position Sensor (TPS) issues: A bad TPS provides incorrect information about the throttle position, affecting fuel delivery.
* Overheating: An overheating engine can shut itself down to prevent damage. Check coolant levels and look for leaks.
Other possibilities:
* Transmission problems: In some cases, transmission issues can cause the engine to stall.
* Vacuum leaks: Leaks in the vacuum system can disrupt engine operation.
Troubleshooting Steps:
To diagnose the problem, you'll need to systematically check these areas. Start with the simple things:
1. Check the battery and alternator: Have them tested at an auto parts store.
2. Check fluid levels: Engine oil, coolant, and power steering fluid.
3. Inspect wiring: Look for any obvious damage or corrosion.
4. Check for any error codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored by the engine's computer. These codes can pinpoint the problem.
If you're not comfortable working on cars yourself, take it to a mechanic for diagnosis and repair. Trying to diagnose this yourself without proper tools and knowledge can be frustrating and potentially dangerous. The problem's complexity could vary significantly based on the engine's particular condition and history.
