High-Probability Issues:
* Fuel Pump/Fuel Filter: A weak fuel pump or clogged fuel filter can't supply enough fuel under load (when you accelerate). This is a very common cause of this symptom. The fuel pump may be failing with age, or the filter may be clogged with debris.
* Mass Airflow Sensor (MAF) Sensor: This sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor will provide inaccurate readings, leading to a lean fuel mixture and causing the engine to sputter or die. Cleaning it (carefully, following instructions) is often a first step.
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle position. A faulty TPS provides inaccurate data, leading to poor fuel delivery and causing the engine to hesitate or die.
* Crankshaft Position Sensor (CKP): This sensor tells the computer the engine's rotational position. A faulty CKP can cause misfires, hesitation, and stalling.
* Ignition System (Spark Plugs, Wires, Distributor): Worn spark plugs, faulty ignition wires, or a failing distributor cap and rotor can lead to misfires, especially under load. This is more likely if you are also experiencing misfires or a rough idle.
Less-Likely (but possible) Issues:
* Fuel Injectors: Clogged or failing fuel injectors can prevent sufficient fuel from reaching the combustion chambers.
* Computer (PCM): While less common, a faulty PCM can cause various drivability issues, including the symptoms you describe. This is usually diagnosed last.
* Vacuum Leaks: Leaks in the vacuum system can disrupt the proper functioning of various engine components, affecting fuel delivery and ignition timing.
* Catalytic Converter: A severely clogged catalytic converter can restrict exhaust flow, leading to a loss of power and potentially stalling.
Troubleshooting Steps:
1. Check the basics: Start with the easiest and cheapest checks. Inspect the air filter (replace if dirty), check all visible vacuum hoses for cracks or leaks, and visually inspect the spark plug wires for damage.
2. Fuel Pressure Test: A fuel pressure test will definitively tell you if the fuel pump and filter are delivering enough fuel. This requires a fuel pressure gauge and some mechanical knowledge.
3. Scan the OBD-II System: Use an OBD-II code reader to check for any diagnostic trouble codes (DTCs) stored in the car's computer. These codes can provide valuable clues to the problem.
4. Professional Diagnosis: If you're not comfortable performing these checks yourself, taking the car to a qualified mechanic is the best course of action. They have the tools and expertise to diagnose the problem accurately and efficiently.
Important Note: Driving a car with these symptoms can be dangerous. If the car is difficult or dangerous to drive, have it towed to a repair shop. Don't attempt to drive it extensively to diagnose the problem yourself.
