1. Fuel System:
* Empty Tank: The most obvious – check the fuel gauge and consider topping it off.
* Fuel Pump Failure: The pump might be malfunctioning, not supplying fuel to the engine. You might hear a buzzing sound from the fuel pump area when you turn the key to the "on" position (but not cranking). This sound indicates the pump is trying to prime, but failing to deliver fuel.
* Clogged Fuel Filter: A dirty fuel filter restricts fuel flow.
* Fuel Injector Problems: Injectors might be clogged, faulty, or not receiving the proper electrical signal.
* Fuel Delivery Lines: Cracks or leaks in the lines can prevent fuel from reaching the engine.
2. Ignition System:
* Dead Battery: Test the battery voltage. A weak or dead battery won't crank the engine.
* Bad Battery Cables: Corroded or loose battery cables can prevent sufficient current flow.
* Starter Motor Issues: The starter could be faulty, not engaging, or receiving insufficient power. You might hear a clicking sound when turning the key.
* Ignition Switch Problems: The switch might be faulty, preventing power from reaching the ignition system.
* Distributor Cap and Rotor: Worn or damaged components can interrupt the spark delivery.
* Ignition Coil: A faulty coil won't produce the high voltage needed for sparking.
* Spark Plugs and Wires: Worn, fouled, or damaged spark plugs or wires prevent a strong spark.
3. Electrical System:
* Fuses and Relays: Check the fuses and relays related to the ignition and fuel systems. A blown fuse or faulty relay can cut off power to essential components.
4. Other Potential Issues:
* Security System: If equipped, a malfunctioning security system could be preventing the engine from starting.
* Neutral Safety Switch: This switch prevents starting unless the transmission is in park or neutral. Make sure the gear selector is in the correct position.
* Crankshaft Position Sensor (CPS): This sensor provides the engine control module (ECM) with information about the crankshaft's position. A faulty CPS will prevent the engine from starting.
* Engine Control Module (ECM): Though less common, a faulty ECM can cause starting issues.
Troubleshooting Steps:
1. Check the obvious: Fuel level, battery voltage, and battery cables.
2. Listen for sounds: A clicking sound might indicate a starter problem; buzzing from the fuel pump area may suggest a fuel pump issue.
3. Visual inspection: Check for any obvious damage to wires, hoses, or components.
4. Test the basics: Test the battery, spark plugs (with a spark tester), and fuel pressure (requires a fuel pressure gauge).
Since this is an older vehicle, some of these issues might be more likely than others. A mechanic with experience in older vehicles would be best suited to diagnose the problem if you are not comfortable working on your car yourself. Providing more details about the symptoms (e.g., does it crank but not start? Do you hear any unusual sounds?) will help narrow down the possibilities.
