1. Fuel System:
* Empty Tank: The most obvious – check your fuel gauge and add fuel if needed.
* Fuel Pump: Listen carefully near the fuel tank while someone cranks the engine. You should hear a whirring sound for a second or two when the key is first turned to the "on" position (before cranking). No whirring suggests a faulty fuel pump, relay, or fuse.
* Fuel Filter: A clogged fuel filter restricts fuel flow. It's relatively inexpensive and easy to replace.
* Fuel Injectors: These could be clogged or malfunctioning. This requires more advanced diagnostics.
* Fuel Pressure: A fuel pressure gauge connected to the fuel rail will tell you if the system has adequate pressure. This requires specialized tools.
2. Ignition System:
* Spark Plugs and Wires: Worn, fouled, or damaged spark plugs and wires prevent ignition. Check for cracks, corrosion, or excessive wear. Replace if necessary. Gap should be checked with a feeler gauge.
* Distributor Cap and Rotor (if equipped): Inspect for cracks, corrosion, or worn contacts.
* Ignition Coil: A faulty coil won't supply the necessary high voltage to the spark plugs. This requires testing with a multimeter or specialized tools.
* Crankshaft Position Sensor (CKP): This sensor tells the computer the engine's rotational position. A faulty sensor prevents proper ignition timing.
3. Starting System:
* Battery: A weak battery might crank the engine slowly, preventing a start. Test the battery voltage with a multimeter. It should be around 12.6V when fully charged.
* Battery Terminals: Corroded terminals can prevent sufficient current flow. Clean them with a wire brush and baking soda.
* Starter: Although it's turning over, a weak starter might not be providing enough power. This requires testing.
4. Computer/Sensor Issues:
* Computer (PCM): A faulty PCM can prevent the engine from starting. This is less common but possible. Diagnosis usually requires a scan tool.
* Other Sensors: Several sensors (e.g., oxygen sensor, coolant temperature sensor) contribute to proper engine operation. A faulty sensor can prevent starting, although less likely to be the *only* reason for no start.
Troubleshooting Steps:
1. Check the obvious: Fuel level, battery terminals.
2. Listen for the fuel pump: Check for the whirring sound when the key is turned to "on."
3. Inspect spark plugs and wires: Look for damage or fouling.
4. Test the battery: Make sure it has sufficient voltage.
5. If you're comfortable, check fuses and relays related to fuel pump and ignition.
If you're not comfortable working on your vehicle yourself, take it to a qualified mechanic. They have the diagnostic tools and expertise to pinpoint the problem accurately and efficiently. Trying to diagnose complex electrical issues without the right tools can lead to further damage or injury.
