Ignition System:
* Cranking but not starting: This suggests the fuel is getting to the engine, but there's no spark or a weak spark. Check the following:
* Ignition Coil: Test the coil for proper resistance and voltage. A failing coil is a common cause of no-start issues.
* Spark Plugs and Wires: Inspect the plugs for fouling, wear, or damage. Check the wires for cracks or fraying. Replace if necessary. A bad plug wire can prevent a cylinder from firing.
* Ignition Control Module (ICM): This component can fail and prevent the spark from reaching the plugs. Testing may require specialized equipment.
* Distributor (if equipped): Inspect the rotor and cap for wear or damage. These are potential points of failure in the ignition system.
* Crankshaft Position Sensor (CKP): This sensor tells the computer the engine's rotational position. A faulty sensor prevents the engine from starting.
* Cam Position Sensor (CMP): Similar to the CKP sensor, a faulty CMP sensor can prevent starting.
Fuel System (Beyond the Pump):
* Fuel Filter: A clogged fuel filter will restrict fuel flow even if the pump works. Replace it.
* Fuel Pressure Regulator: While the pump might be supplying pressure, the regulator could be failing, leading to insufficient fuel pressure at the injectors.
* Fuel Injectors: They might be clogged or electrically faulty, preventing fuel delivery to the combustion chambers. Testing injectors usually requires specialized tools.
Other Potential Issues:
* Battery and Connections: A weak battery or corroded terminals can prevent sufficient cranking power. Test the battery voltage and clean the terminals.
* Starter Motor: While it cranks, a weak starter might not provide enough power to turn the engine over reliably.
* Security System: If the car has an immobilizer, a problem with the key or the system itself could prevent starting.
* Computer (PCM): A faulty PCM can cause numerous starting issues. Diagnosis usually requires a scan tool.
Troubleshooting Steps:
1. Check for codes: Use an OBD-II scanner to retrieve any diagnostic trouble codes (DTCs). This will often pinpoint the problem.
2. Visual Inspection: Carefully inspect all components mentioned above for any visible damage.
3. Test Components: Use a multimeter to test the battery, coil, sensors, and other components as needed. You might need a specialized scan tool to test some components or diagnose the PCM.
4. Seek Professional Help: If you're not comfortable working on your car's electrical system, take it to a qualified mechanic. They have the tools and expertise to diagnose the problem effectively.
The Catera's age increases the chances of multiple failing components. Systematic checking of the ignition system followed by the fuel delivery system is the most effective approach. Remember safety precautions when working with the electrical system of your car.
