* Crankshaft Position Sensor (CKP): This is a very common culprit. As the sensor heats up, it can malfunction, leading to misfires and stalling. The engine needs the CKP signal to know where the pistons are and properly time the spark.
* Ignition System Problems: Worn distributor cap, rotor, spark plug wires, or failing ignition coil can all cause misfires, especially when the engine is hot. The increased heat exacerbates any existing weaknesses.
* Fuel Delivery Issues: A failing fuel pump that can't keep up with demand under load (while driving), but struggles even more when the engine speed drops at idle, is possible. A clogged fuel filter can also contribute. Heat soak can affect fuel pump performance.
* Throttle Position Sensor (TPS): An inaccurate TPS reading can cause the engine to misfire or stall, particularly at idle. Heat can affect its accuracy.
* Mass Airflow Sensor (MAF): A dirty or failing MAF sensor provides incorrect air-fuel mixture data to the computer, resulting in poor running or stalling. While less directly heat-related than some others, prolonged heat can damage it.
* Coolant Temperature Sensor (CTS): This sensor tells the computer the engine temperature. An inaccurate reading can lead to incorrect fuel mixture and timing, particularly when the engine is hot.
* Vacuum Leaks: A leak in the vacuum system can cause erratic idle and stalling. These can be difficult to find.
* Engine Coolant: Low coolant levels can cause overheating and subsequent stalling. Check your coolant reservoir!
Troubleshooting Steps (in order of ease):
1. Check Engine Coolant: The easiest and safest first step. Low coolant can cause overheating and lead to numerous issues.
2. Check Engine Light: See if there's a diagnostic trouble code (DTC) stored in the computer's memory. A code reader (available cheaply at auto parts stores) can read this. The code will give you a much better clue.
3. Inspect Ignition System: Visually inspect the distributor cap, rotor, and spark plug wires for cracks, damage, or corrosion. These are relatively inexpensive to replace.
4. Check for Vacuum Leaks: Listen carefully around the engine while it's running for any hissing sounds. This requires some experience, but a spray bottle with soapy water near potential vacuum lines can help pinpoint leaks.
Important Note: Without a diagnostic code, pinpointing the exact cause is difficult. Getting the codes read by a code reader is highly recommended as a first step. If you're not comfortable working on your car, take it to a mechanic. Ignoring the problem could lead to more severe engine damage.
