* Crankshaft Position Sensor (CKP Sensor): This sensor tells the computer the position of the crankshaft. If it's faulty or failing, the computer won't know when to fire the spark plugs, leading to immediate shutdown. This is a very common cause of this problem.
* Cam Position Sensor (CMP Sensor): Similar to the CKP sensor, but for the camshaft. A faulty CMP sensor will also prevent proper timing and cause the engine to die.
* Fuel Pump: If the fuel pump isn't delivering fuel, the engine will start and quickly die. This could be due to a faulty pump, a clogged fuel filter, or issues within the fuel delivery system. Listen carefully – you should hear a whirring sound from the fuel pump when you first turn the key to the "on" position (before cranking). If you don't hear it, that's a strong suspect.
* Mass Airflow Sensor (MAF Sensor): This sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor can cause the engine to run lean and stall.
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle's position. A faulty TPS can lead to erratic engine behavior and stalling.
* Ignition System Problems: This could include a failing ignition coil, bad spark plugs, or worn-out spark plug wires. A weak spark won't sustain combustion.
* Low Fuel: Though obvious, make sure the car has sufficient fuel.
* Battery/Alternator: While less likely to cause an immediate shutdown, a very weak battery or a completely failed alternator could lead to insufficient power for the engine to run consistently.
Troubleshooting Steps:
1. Check for Error Codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in the car's computer. These codes will often point directly to the faulty component.
2. Check Fuel Pressure: This requires a fuel pressure gauge and some mechanical knowledge. Low fuel pressure points to a fuel delivery issue.
3. Inspect the Simple Stuff First: Ensure the battery terminals are clean and tight, and that the car has enough fuel.
4. Visual Inspection: Look for any obvious damage to wiring harnesses, especially around the sensors mentioned above.
5. Check for Vacuum Leaks: Vacuum leaks can disrupt the air-fuel mixture. Listen carefully for any hissing sounds near the intake manifold.
Important Note: If you're not comfortable working on your car, take it to a qualified mechanic for diagnosis and repair. Improperly diagnosing and attempting to fix these issues could lead to further damage or injury. The sensors mentioned above are relatively inexpensive to replace, but labor costs can quickly add up if a mechanic needs to diagnose the problem.
