* Crankshaft Position Sensor (CKP Sensor): This sensor tells the computer the position of the crankshaft. If it's faulty, the computer won't know when to fire the spark plugs, resulting in no start. This is a very common cause of no-start issues even with spark.
* Camshaft Position Sensor (CMP Sensor): Similar to the CKP sensor, a faulty CMP sensor prevents the computer from synchronizing the spark and fuel injection.
* Ignition Control Module (ICM): This module controls the ignition system. A faulty ICM can prevent spark from reaching the plugs, although you say you *have* spark, so this is less likely but worth considering if the spark is weak or inconsistent. A faulty ICM can sometimes exhibit intermittent behavior.
* Spark Plug Wires: While you say you have spark, double-check the spark plug wires to ensure they're securely connected and not damaged or cracked. A bad connection or wire can result in weak or intermittent spark, even if you see some.
* Low Compression: Although the engine is turning, low compression in one or more cylinders would prevent proper combustion, even with fuel and spark. You'll need a compression tester to diagnose this. Low compression can be caused by worn rings, valves, or a blown head gasket.
* Fuel Injector Problem (unlikely but possible): While you say it gets fuel to the motor, verify that fuel is *actually* being injected into the cylinders. A clogged injector or faulty injector control module could be preventing proper fuel delivery, even if fuel reaches the engine.
* Security System: Does your car have a factory anti-theft system? A malfunctioning immobilizer could prevent the engine from starting even if everything else seems fine.
Troubleshooting Steps:
1. Check for Strong Spark: Don't just assume you have spark. Use an inline spark tester to verify strong spark at each cylinder. Weak spark can be misinterpreted as "spark."
2. Check CKP and CMP Sensors: These are relatively inexpensive and easy to replace. A diagnostic scan tool can often read codes indicating a problem with these sensors.
3. Compression Test: Rent or borrow a compression tester to check the compression in each cylinder. Low compression in one or more cylinders points to a major engine problem.
4. Diagnostic Scan: Have the car scanned for trouble codes using an OBD-II scanner. This can point towards the specific sensor or system at fault.
5. Fuel Injector Test: This requires more advanced tools but can check if injectors are delivering the correct amount of fuel.
If you're not comfortable performing these checks yourself, take it to a qualified mechanic. They have the tools and expertise to diagnose the problem quickly and accurately. The more information you can give them (e.g., "I have spark but it seems weak," or "the engine cranks but sounds rough"), the better they can assist you.
