Common Causes:
* Dead or Dying Battery: This is the most frequent culprit. A weak battery might have enough power to crank the engine initially, but not enough to sustain it once it's running. Test the battery voltage with a multimeter. A voltage below 12.6V when the car is off indicates a weak battery.
* Faulty Alternator: The alternator charges the battery while the engine is running. If it's failing, it won't recharge the battery, and the car will die as soon as the battery's initial charge is depleted. Have the alternator tested at an auto parts store or mechanic.
* Starter Problems: While the starter is primarily responsible for *cranking* the engine, a problem with it (worn-out solenoid, faulty motor) could cause the engine to stop immediately after starting. A clicking sound when you turn the key is a strong indicator of a starter issue.
* Fuel Delivery Problems:
* Fuel Pump: A failing fuel pump may be able to provide enough fuel for the initial start but not enough to sustain the engine.
* Fuel Filter: A clogged fuel filter restricts fuel flow.
* Fuel Injectors: Clogged or malfunctioning fuel injectors may not deliver fuel consistently.
* Ignition System Problems:
* Ignition Coil: A faulty ignition coil can prevent consistent spark delivery to the engine.
* Spark Plugs/Wires: Worn or damaged spark plugs or wires can lead to misfires and stalling.
* Crankshaft Position Sensor (CKP): This sensor tells the engine's computer where the crankshaft is. A faulty CKP will prevent the engine from running consistently.
* Cam Position Sensor (CMP): Similar to the CKP, a faulty CMP can cause the engine to stall.
* Engine Control Module (ECM) Problems: The ECM is the "brain" of the car. A malfunctioning ECM can cause a variety of issues, including stalling.
* Security System Issues: Some car alarm or immobilizer systems might be interfering with the engine's operation.
* Loose or Corroded Connections: Check battery terminals, ground connections, and other electrical connections for corrosion or looseness.
Troubleshooting Steps:
1. Check the Battery: Test the voltage. If low, jump-start the car. If it dies again quickly, the battery or alternator is likely the problem.
2. Listen for Unusual Sounds: Pay attention to any clicking, grinding, or unusual noises when you try to start the car.
3. Check Engine Light: Is the check engine light on? If so, have the codes read at an auto parts store (often free) to identify potential issues.
4. Inspect Wiring and Connections: Look for any loose, corroded, or damaged wires and connectors, especially around the battery and starter.
5. Professional Diagnosis: If you can't identify the problem yourself, take your car to a mechanic for a professional diagnosis.
It's impossible to pinpoint the exact cause without more information or a physical inspection. The steps above should help you narrow down the possibilities. Remember safety first – if you're not comfortable working on your car, take it to a qualified mechanic.
