* Crankshaft Position Sensor (CKP Sensor): This sensor tells the engine's computer where the crankshaft is. A faulty CKP sensor can cause the engine to stall unexpectedly. If it's intermittent, it might work again after a short time.
* Cam Position Sensor (CMP Sensor): Similar to the CKP sensor, but for the camshaft. A faulty CMP sensor will also cause the engine to die unexpectedly.
* Mass Airflow Sensor (MAF Sensor): This sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor can cause the engine to run poorly or stall, especially under load.
* Fuel Pump Relay: This relay controls the power to the fuel pump. An intermittent failure could cut off fuel, causing the car to stall, then work again later.
* Fuel Pump itself: A failing fuel pump might not always provide sufficient pressure, leading to stalling, particularly under load or when the fuel tank is low. However, it's less likely to recover without intervention unless the issue is extremely intermittent.
* Ignition Switch: While less common, a failing ignition switch can intermittently interrupt the power supply to the engine.
* Wiring Issues: Loose, corroded, or damaged wiring in the engine bay can cause intermittent interruptions to power or signals to various components. This is a broad category, so diagnosing this would require more investigation.
* Alternator (less likely): While a failing alternator would eventually leave you stranded, it's less likely to be the cause if the car restarts without a jump. It would point towards a charging issue and the battery draining eventually if it was the main culprit.
Troubleshooting Steps:
1. Check the engine codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in the car's computer. These codes will often point directly to the faulty component.
2. Inspect the fuel system: Check the fuel pressure. You'll likely need a fuel pressure gauge for this. Low fuel pressure indicates a problem with the fuel pump, filter, or pressure regulator.
3. Check for loose or corroded connections: Carefully inspect all wiring harnesses and connectors in the engine bay, especially those related to the sensors mentioned above.
4. Have the sensors tested: A mechanic can test the CKP, CMP, and MAF sensors to verify their functionality. These are relatively inexpensive parts to replace if faulty.
Important Note: It's difficult to diagnose this problem without more information and some testing. If the problem continues, it's best to have a qualified mechanic diagnose and repair the issue. Driving a car with intermittent engine stalling is unsafe.
