* Fuel Pump: The most likely culprit. The fuel pump might be weakening with age and heat. After running for a while, it might not be able to supply enough fuel under pressure, especially when idling (demand is slightly higher then) or after a refill (slight shift in pressure/position). The cooling down period allows it to recover enough to restart.
* Fuel Filter: A clogged fuel filter restricts fuel flow, exacerbating a weak pump issue. This is a relatively inexpensive part to replace.
* Crankshaft Position Sensor (CKP): Heat can affect this sensor's performance. It tells the engine where the crankshaft is, crucial for ignition timing. A failing sensor might cause the engine to stall, especially after prolonged running.
* Mass Airflow Sensor (MAF): A dirty or failing MAF sensor provides inaccurate air readings to the engine computer, leading to a poor air-fuel mixture and potential stalling.
* Ignition Coil/Spark Plugs/Wires: While less likely given the specifics, these components could be breaking down under heat. Weak sparks could cause misfires and stalling, particularly after the engine's components have warmed up considerably.
* Fuel Pressure Regulator: This could be failing and allowing fuel pressure to drop too low when the engine is hot.
Troubleshooting Steps:
1. Check the fuel filter: This is the easiest and cheapest thing to do first. Replace it if it's dirty or old.
2. Check fuel pressure: This requires a fuel pressure gauge and some mechanical skill. This will directly tell you if the fuel pump is delivering adequate pressure. Low pressure after running is highly suggestive of a pump problem.
3. Inspect the fuel pump relay: Ensure it's clicking when the ignition is on.
4. Check the MAF sensor: Inspect it for dirt or damage. You might be able to clean it with MAF sensor cleaner, but replacement is often preferable.
5. Check the CKP sensor: This can be tricky, often involving specific diagnostic tools or a mechanic.
6. Inspect spark plugs and wires: Look for any visible signs of wear or damage. Wires should be free of cracks, and spark plugs should have the correct gap.
Important Note: If you're not comfortable working on your car's systems yourself, take it to a qualified mechanic. Ignoring this problem could lead to more serious damage. The intermittent nature of the issue makes diagnosis slightly more challenging. A professional with diagnostic tools can accurately pinpoint the cause more quickly.
