* Fuel Filter: A clogged fuel filter restricts fuel flow to the engine. If the engine cranks but doesn't fire, it's a strong indicator that insufficient fuel is reaching the combustion chamber.
* Fuel Pump: A failing fuel pump might not deliver enough fuel pressure, or might not deliver fuel at all. This would also prevent the engine from starting, even if it cranks.
However, it's important to note: Cranking but not starting can have many other causes, including:
* Spark plugs: Worn, fouled, or damaged spark plugs prevent ignition.
* Ignition coil: A faulty ignition coil won't provide the necessary spark.
* Distributor (if applicable): Problems with the distributor can affect spark delivery.
* Crankshaft Position Sensor (CKP sensor): This sensor tells the computer the engine's rotational position. A faulty sensor can prevent the engine from starting.
* Cam Position Sensor (CMP sensor): Similar to the CKP, but monitors the camshaft.
* Low fuel: Believe it or not, sometimes the simplest explanation is the right one. Make sure your tank isn't nearly empty.
* Security system: A malfunctioning immobilizer or alarm system can prevent starting.
* Battery cables: Loose or corroded battery cables can impede current flow.
Troubleshooting Steps:
Before replacing parts, it's best to try some basic troubleshooting:
1. Check the fuel level: Make sure the gas tank isn't nearly empty.
2. Listen for the fuel pump: When you turn the key to the "on" position (but before cranking), you should hear a brief hum from the fuel pump. If you don't hear it, the pump might be faulty.
3. Check fuel pressure: This requires a fuel pressure gauge and some mechanical knowledge. Low fuel pressure points to a problem with the pump or filter.
4. Check for spark: Use a spark tester to check if spark plugs are getting spark.
Replacing the fuel filter is a relatively inexpensive and easy repair (DIY-able for many). Replacing the fuel pump is more involved and may require professional help. It's generally recommended to troubleshoot the simpler, cheaper options first.
