Fuel System Problems:
* Clogged Fuel Filter: A dirty fuel filter restricts fuel flow, and the engine might start briefly before dying as it runs out of readily available fuel. This is a cheap and easy check.
* Fuel Pump Failure: The fuel pump might be weak, failing to provide sufficient pressure, or it could be completely dead. You'll hear the pump whirring briefly when you turn the key to the "on" position before cranking - if you don't hear it, that's a strong indicator.
* Low Fuel: Seems obvious, but make sure the tank isn't nearly empty.
* Fuel Pressure Regulator: This regulates the fuel pressure to the injectors. A faulty regulator can cause erratic fuel delivery or low pressure.
* Clogged Fuel Injectors: Dirty or clogged injectors can prevent sufficient fuel from reaching the engine's cylinders.
* Fuel Pump Relay: The relay may be faulty, preventing power from reaching the fuel pump.
Ignition System Problems:
* Crankshaft Position Sensor (CKP Sensor): This sensor tells the computer the position of the crankshaft, which is crucial for ignition timing. A faulty sensor will cause the engine to die.
* Distributor Cap and Rotor: These components distribute the high-voltage spark to the spark plugs. Corrosion, cracks, or wear can interrupt the spark.
* Worn Spark Plugs or Wires: These are essential for ignition. Worn plugs or wires can cause misfires and stalling.
* Ignition Coil: The coil provides the high voltage for the spark plugs. A weak or failing coil can lead to intermittent or no spark.
* Ignition Control Module (ICM): This module controls the ignition system. A faulty ICM can cause all sorts of ignition problems.
Other Potential Problems:
* Mass Airflow Sensor (MAF Sensor): This sensor measures the amount of air entering the engine. A faulty sensor can provide incorrect data, leading to a lean fuel mixture and stalling.
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle position. A faulty TPS can cause erratic idle and stalling.
* Vacuum Leaks: Leaks in the vacuum system can disrupt the engine's operation.
* Computer Issues (ECM): While less common, a faulty engine control module (ECM) can cause various problems, including stalling.
Troubleshooting Steps:
1. Check the obvious: Fuel level, listen for the fuel pump prime, and visually inspect the spark plug wires for damage.
2. Check for codes: Use an OBD-I scanner (you'll need one specific to older vehicles) to check for diagnostic trouble codes (DTCs). This can pinpoint the problem area.
3. Test fuel pressure: A fuel pressure gauge is needed to test the fuel system pressure. This is a more advanced step.
4. Check spark: Remove a spark plug, ground it, and crank the engine to see if you're getting spark. (Be careful – spark plugs are hot!)
5. Inspect distributor cap and rotor: Look for cracks, corrosion, or worn contacts.
This is a complex problem, and diagnosing it requires systematic troubleshooting. If you're not comfortable working on your car yourself, take it to a mechanic. Providing more information (e.g., does it crank normally? Any unusual noises? Does the engine sputter before dying?) will help narrow down the possibilities.
