Fuel System:
* Fuel Pump: A failing fuel pump might not be delivering enough fuel to the engine, causing it to stall, especially under load (going uphill or accelerating).
* Fuel Filter: A clogged fuel filter restricts fuel flow, leading to similar symptoms as a failing fuel pump.
* Fuel Injector(s): Clogged or faulty fuel injectors can prevent proper fuel delivery to the cylinders.
* Fuel Pressure Regulator: A malfunctioning regulator can cause inconsistent fuel pressure.
Ignition System:
* Distributor Cap and Rotor: Worn or damaged parts in the distributor can interrupt the spark to the plugs. (If your Lesabre has a distributor - some later models might have coil-on-plug ignition).
* Ignition Coil: A failing ignition coil won't produce sufficient spark to ignite the fuel-air mixture.
* Spark Plugs and Wires: Worn or damaged spark plugs and wires can lead to misfires and stalling.
* Crankshaft Position Sensor (CKP Sensor): This sensor tells the computer the engine's rotational speed. A faulty sensor can cause the engine to stall.
* Cam Position Sensor (CMP Sensor): Similar to the CKP sensor, but it monitors the camshaft's position. A faulty sensor can cause similar problems.
Other Potential Issues:
* Mass Airflow Sensor (MAF Sensor): This sensor measures the amount of air entering the engine. A faulty sensor can cause the engine to run lean or rich, leading to stalling.
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle position. A faulty sensor can cause erratic engine behavior.
* Alternator: A failing alternator won't charge the battery, eventually leading to the engine dying when the battery is depleted. Check your battery voltage.
* Battery: A weak or dying battery can cause similar problems.
* Vacuum Leaks: Leaks in the vacuum system can disrupt the engine's operation.
* Computer/ECM Problems: While less common, a problem with the engine control module (ECM) can cause a variety of issues, including stalling.
Troubleshooting Steps:
1. Check the obvious: Start with the easiest checks – battery voltage, check engine light (if illuminated, get the codes read), and look for any obvious signs of damage (loose wires, cracked hoses).
2. Get diagnostic codes read: A diagnostic scan tool can read trouble codes stored in the ECM, pointing you towards the problem area. Auto parts stores often offer this service for free.
3. Check the basics: Inspect your spark plugs, wires, and distributor cap/rotor (if applicable) for wear and tear.
4. Professional Help: If you're not comfortable working on your car, take it to a qualified mechanic for diagnosis and repair. This is especially important if you're unsure about any step of the troubleshooting process.
Remember safety first. If your car is dying while driving, pull over to a safe location as soon as possible. Continuing to drive with a malfunctioning engine can be dangerous.
