* Cranking Speed: While the starter motor *works*, is it cranking the engine over *fast enough*? A slow cranking speed can prevent the engine from firing, even with fuel, spark, and compression. Check the battery voltage and the condition of the battery terminals and cables. A weak battery or poor connections will cause slow cranking.
* Timing: The ignition timing might be significantly off. If the spark plugs are firing too early or too late relative to the piston position, the engine won't start. This requires a timing light to diagnose.
* Ignition Control Module (ICM): This component controls the ignition system. A faulty ICM can prevent spark delivery, even if you have spark in some situations. This is a common failure point on some Ford vehicles.
* Crankshaft Position Sensor (CKP): This sensor tells the computer where the crankshaft is in its rotation. A faulty CKP sensor will prevent the computer from correctly timing the ignition and fuel injection, leading to a no-start condition.
* Cam Position Sensor (CMP): Similar to the CKP sensor, a faulty CMP sensor affects the ignition timing and fuel injection.
* Fuel Injectors: Although you say you have fuel, are the injectors actually *delivering* fuel into the cylinders? A clogged injector or a faulty injector control module could prevent fuel delivery. A fuel pressure test is needed.
* Air Intake System: Make sure there are no obstructions in the air intake system. A completely blocked intake will prevent the engine from running.
Troubleshooting Steps:
1. Battery and Connections: Check the battery voltage with a multimeter. Clean the battery terminals and cable ends thoroughly. Test the cables for resistance.
2. Cranking Speed: Observe how quickly the engine cranks over. Slow cranking points to a battery, starter motor, or poor connections issue.
3. Spark Test: While you say you have spark, verify it's strong and consistent across all cylinders using a spark tester. Weak spark is common in no-start situations.
4. Fuel Pressure Test: This is crucial. Use a fuel pressure gauge to check if the fuel pressure is within specifications. Low pressure indicates a problem with the fuel pump, fuel filter, or fuel pressure regulator.
5. Check for Codes: Use an OBD-II scanner to check for diagnostic trouble codes (DTCs). These codes can pinpoint the problem.
6. Visual Inspection: Inspect all wiring harnesses and components for any obvious damage.
7. Professional Help: If you're not comfortable performing these tests, take it to a mechanic. Diagnosing a no-start condition can be challenging, and a professional can quickly identify the cause.
Without more information, it's difficult to pinpoint the exact problem. The troubleshooting steps above should help you narrow it down. Remember safety first – always disconnect the battery negative terminal before working on any electrical components.
