* Crankshaft Position Sensor (CKP): This is a very common cause. The CKP sensor tells the computer the engine's rotational position, crucial for timing the fuel injection and spark. A failing CKP can cause the engine to stall immediately or after a few seconds, and will often trigger the check engine light. The light might go off if the sensor is intermittently failing.
* Cam Position Sensor (CMP): Similar to the CKP, the CMP sensor tells the computer the camshaft's position. A faulty CMP will have similar effects to a bad CKP, causing stalling and potentially triggering the check engine light. On some engines, the light may not always come on.
* Fuel Pump: A weak or failing fuel pump might be able to provide enough fuel to start the engine briefly, but then it struggles to maintain pressure, leading to a stall. The check engine light *might* come on, depending on the nature of the failure (if the computer detects low fuel pressure).
* Fuel Filter: A clogged fuel filter restricts fuel flow. This might allow the engine to start briefly before starving it of fuel. The check engine light probably *won't* come on with this issue.
* Ignition System Problems: While less likely to cause immediate stalling, a weak ignition coil, faulty distributor cap, rotor, or spark plug wires could contribute. Misfires can lead to stalling eventually and might trigger the check engine light, often accompanied by rough running before stalling.
* Mass Airflow Sensor (MAF): A dirty or faulty MAF sensor can provide incorrect information about the air intake, leading to a lean fuel mixture and stalling. This is more likely to cause a persistent check engine light than an intermittent one.
* Throttle Position Sensor (TPS): A malfunctioning TPS can give incorrect readings to the computer about throttle position, leading to incorrect fuel delivery and potential stalling. This too might or might not set a check engine light.
Troubleshooting Steps:
1. Check the Check Engine Light Codes: You'll need an OBD-I code reader (specific to pre-OBD-II vehicles, from 1996 on). This will give you a clue about the specific problem the computer has detected.
2. Inspect Fuel System: Visually check the fuel lines for cracks or leaks. Listen for the fuel pump's whirring sound when you turn the key to the "on" position (before cranking). A weak or absent sound indicates a problem.
3. Check Ignition System: Inspect distributor cap, rotor, spark plug wires for cracks, wear, or corrosion. If possible, test the coil.
4. Check the Sensors (CKP, CMP, TPS, MAF): This often requires some automotive diagnostic experience or a scanner that can perform live data monitoring to check sensor readings.
It's impossible to pinpoint the exact cause without diagnostics. Start with the check engine light codes and then systematically investigate the most likely culprits based on the information you gather. If you're not comfortable working on vehicles, a qualified mechanic is the best option to diagnose and repair the problem safely.
