Electrical System Problems:
* Alternator: This is a very common cause. The alternator charges the battery. If it fails, the battery will drain, causing the engine to stall. Check the charging system voltage with a multimeter.
* Battery: A weak or failing battery can also lead to stalling. Have the battery tested for its ability to hold a charge and its cranking amps. Corrosion on the battery terminals can also prevent proper power flow.
* Ignition Switch: A faulty ignition switch can interrupt the power supply to the engine.
* Wiring Issues: Corrosion, loose connections, or damaged wiring harnesses anywhere in the electrical system can interrupt power to critical components. This is especially true in older vehicles prone to rust and wear.
* Crankshaft Position Sensor (CKP): This sensor tells the engine's computer where the crankshaft is. A faulty sensor can cause the engine to stall unexpectedly.
* Cam Position Sensor (CMP): Similar to the CKP sensor, a faulty CMP sensor will disrupt the timing of the engine and cause it to stall.
Fuel System Problems:
* Fuel Pump: A failing fuel pump won't deliver enough fuel to the engine, leading to stalling. You might hear a whirring noise from the fuel pump when you turn the key to the "on" position. If it's faint or non-existent, it's a suspect.
* Fuel Filter: A clogged fuel filter restricts fuel flow, eventually leading to the engine stalling.
* Fuel Injectors: Clogged or faulty fuel injectors won't deliver the necessary fuel to the cylinders.
Other Potential Causes:
* Transmission Problems: While less likely to cause a complete shut-off, transmission issues *could* contribute if the engine is starved of power due to a transmission malfunction.
* Overheating: An overheating engine will often shut itself down to prevent damage. Check the coolant level and look for signs of leaks.
* Vacuum Leaks: Leaks in the vacuum lines can disrupt the engine's operation and cause it to stall.
* Computer Issues (PCM): The Powertrain Control Module (PCM) is the "brain" of the engine. A faulty PCM can cause a variety of problems, including stalling.
Troubleshooting Steps:
1. Check the obvious: Battery terminals (clean them), coolant level, and oil level.
2. Have the battery and alternator tested: This is the most important first step.
3. Listen for unusual noises: Whirring from the fuel pump, unusual engine sounds, etc.
4. Check engine codes: Use an OBD-II scanner to retrieve any diagnostic trouble codes (DTCs) stored by the vehicle's computer. These codes will point you in the right direction. A 1995 model might require a scanner specifically for OBD-I.
It's impossible to diagnose the exact problem remotely. The best approach is to take the vehicle to a qualified mechanic for diagnosis and repair. They have the tools and expertise to properly identify and fix the underlying issue. Providing them with any information you've gathered (e.g., when it stalls, any warning lights, etc.) will help them narrow down the possibilities.
