* Crankshaft Position Sensor (CKP): This sensor tells the engine's computer where the crankshaft is in its rotation. A faulty CKP sensor will prevent the engine from starting or cause it to shut down soon after starting because the computer can't properly time the fuel injection and ignition. This is a very common cause of this type of problem.
* Cam Position Sensor (CMP): Similar to the CKP sensor, but for the camshaft. A faulty CMP sensor leads to similar symptoms.
* Ignition System Problems: This includes the ignition coil(s), spark plug wires, and spark plugs themselves. If the spark is weak or intermittent, the engine won't run reliably. Worn or fouled spark plugs are a common suspect.
* Fuel Delivery Issues: Problems with the fuel pump (weak pump, clogged filter), fuel pressure regulator, or fuel injectors can prevent sufficient fuel from reaching the engine. The car might start briefly on residual fuel, then die.
* Mass Airflow Sensor (MAF) Sensor: This sensor measures the amount of air entering the engine. A faulty MAF sensor can cause the engine to run lean (not enough fuel), leading to stalling.
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle's position. A faulty TPS can cause erratic engine behavior and stalling.
* Computer/ECM Problems: While less common, a faulty Engine Control Module (ECM) or a problem with its programming can cause intermittent starting and stalling.
* Security System Issues: The car's immobilizer system might be malfunctioning, preventing the engine from starting even if the key is recognized.
* Alternator (Less Likely): While you mentioned the car has power, a failing alternator might not provide enough power consistently to keep the engine running. This would typically manifest as dimming lights or other electrical issues as well.
Troubleshooting Steps:
1. Check for diagnostic trouble codes (DTCs): Use an OBD-II scanner to retrieve any stored error codes. These codes can significantly narrow down the possibilities.
2. Inspect the obvious: Check for loose or corroded connections in the engine bay, particularly those related to the sensors mentioned above.
3. Focus on the Sensors: Given the symptoms, start by testing or replacing the CKP and CMP sensors. They are relatively inexpensive and easy to replace (depending on your mechanical skills).
4. Fuel System Check: Listen carefully for the fuel pump whirring when you turn the key to the "on" position (but not cranking). A weak or absent sound indicates a fuel pump issue.
5. Spark Check: If you have some basic automotive knowledge, check for spark at the spark plugs.
It's highly recommended to have a qualified mechanic diagnose the problem if you're not comfortable working on your car yourself. The symptoms point to a fundamental issue preventing the engine from running consistently, and improper diagnosis could lead to further damage or unnecessary expense.
