* Ignition System: Heat can cause components in the ignition system to malfunction. This could include:
* Distributor cap and rotor: Cracks or carbon buildup can worsen with heat, leading to poor spark delivery and stalling.
* Ignition coil: Heat can weaken the coil's ability to generate a strong spark.
* Ignition wires: Worn or damaged wires are more prone to shorting or failing under heat stress.
* Fuel System: Heat significantly impacts fuel performance.
* Fuel pump: A failing fuel pump may not be able to supply enough fuel under high temperatures, especially when the engine is under load.
* Fuel injectors: Clogged or malfunctioning injectors can deliver inconsistent fuel, leading to stalling, especially when hot.
* Fuel filter: A clogged fuel filter restricts fuel flow, making the problem worse under heat.
* Cooling System: While seemingly unrelated, overheating can indirectly cause stalling.
* Overheating: If the engine overheats, it can cause damage to various components, potentially leading to stalling. This could be due to a faulty thermostat, radiator, water pump, or low coolant.
* Mass Airflow Sensor (MAF) Sensor: A faulty MAF sensor can provide inaccurate readings to the engine control unit (ECU), leading to poor fuel mixture and stalling, especially when the air is hot and dense.
* Engine Sensors: Various other sensors (like the coolant temperature sensor) can malfunction with prolonged heat exposure, providing the ECU with incorrect information which leads to improper fuel/air mixtures.
* Electrical Connections: Heat can cause loose or corroded electrical connections to fail intermittently.
Troubleshooting Steps:
To diagnose the problem, you'll want to start with the simplest and safest checks first:
1. Check coolant levels: Ensure the coolant is at the correct level and the system isn't leaking.
2. Inspect the ignition system: Visually check the distributor cap, rotor, and wires for cracks, burns, or corrosion.
3. Check for any obvious vacuum leaks: A vacuum leak can make the engine run poorly, particularly when hot.
4. Test the fuel pressure: A fuel pressure gauge is needed to determine if the fuel pump is delivering enough fuel.
If you're not comfortable performing these checks yourself, take your Ford Tempo to a qualified mechanic for a proper diagnosis. They'll have the tools and expertise to pinpoint the exact cause and fix the issue. Remember to mention the fact that it only stalls in hot weather—this is crucial information for the diagnosis.
