1. Check the Basics:
* Battery Voltage: Make sure the battery is fully charged and the terminals are clean and tight. Low voltage can affect the ignition system. Use a multimeter to check voltage.
* Fuses and Relays: Inspect all fuses and relays related to the ignition system (check your owner's manual for locations and diagrams). A blown fuse or a faulty relay will prevent the system from functioning.
* Ignition Switch: A faulty ignition switch can prevent power from reaching the ignition components. Try wiggling the key while in the "on" position to see if it intermittently works. This is a less common culprit but worth checking.
2. Investigate the Ignition System Components:
* Crankshaft Position Sensor (CKP Sensor): This sensor tells the engine control module (ECM) the position of the crankshaft. Without this information, the ECM won't send a spark signal. A faulty CKP sensor is a very common cause of no-spark conditions. You'll need a multimeter or a scan tool to test its output.
* Camshaft Position Sensor (CMP Sensor): Similar to the CKP sensor, the CMP sensor tells the ECM the position of the camshaft. Some systems rely on this signal. Testing is similar to the CKP sensor.
* Ignition Control Module (ICM): This module receives signals from the sensors and sends the spark signal to the coil. Testing an ICM requires more advanced tools or replacement for definitive diagnosis.
* Ignition Coil(s): The coil(s) boost the low voltage from the ICM to create the high voltage needed for the spark plugs. A visual inspection for cracks or damage is a good starting point. A multimeter can test the coil's primary and secondary windings, but a specific coil tester is preferable.
* Spark Plug Wires: Inspect the wires for cracks, damage, or loose connections. A bad wire can prevent spark from reaching a plug.
* Spark Plugs: While unlikely to cause *no* spark, worn or fouled spark plugs can weaken the spark significantly. Inspect them and consider replacement.
3. Diagnostic Tools:
* Multimeter: Essential for checking voltage and testing components.
* Scan Tool (OBD-II): A scan tool can read diagnostic trouble codes (DTCs) from the ECM, which can pinpoint the problem. Many inexpensive OBD-II readers are available. Older vehicles may need a different type of scanner.
4. Troubleshooting Steps:
1. Start with the easiest checks: Battery, fuses, relays.
2. Check the CKP and CMP sensor signals. If you're comfortable, you can check sensor output using a multimeter, following a wiring diagram.
3. Visual inspection: Look for obvious signs of damage to wires, connectors, and components.
4. Use a scan tool: Read any DTCs.
5. Test the ignition coil(s): If you suspect coil failure, test them with a multimeter or a coil tester.
Important Notes:
* Safety First: Disconnect the negative battery terminal before working on any electrical components.
* Wiring Diagrams: A wiring diagram specific to your vehicle's year and model is invaluable. You can find these online (often on repair manual sites) or in a repair manual.
* Professional Help: If you're not comfortable working on your vehicle's electrical system, take it to a qualified mechanic. Incorrect diagnosis or repairs can cause further damage.
The fact that you have power to the injectors suggests a problem isolated to the ignition system, but without further testing, pinpointing the exact faulty component is difficult. The CKP sensor is a strong suspect, however.
