Fuel System Problems:
* Fuel pump failure: If the fuel pump isn't delivering enough fuel, the engine will idle but starve for fuel under load.
* Clogged fuel filter: A dirty fuel filter restricts fuel flow, causing similar issues to a failing fuel pump.
* Faulty fuel injectors: If one or more injectors are clogged or malfunctioning, the engine won't get the fuel it needs under load.
* Low fuel pressure: This could be caused by a variety of issues, including a leaking fuel line or a faulty fuel pressure regulator.
Ignition System Problems:
* Spark plug issues: Worn, fouled, or damaged spark plugs can cause misfiring, especially under load.
* Spark plug wires: Damaged or loose spark plug wires can lead to a weak or lost spark, causing misfiring.
* Ignition coil failure: If the ignition coil isn't generating enough voltage, the spark plugs won't fire properly.
* Distributor cap and rotor problems: Worn or damaged components in the distributor can cause a weak spark or misfiring.
Air Intake System Problems:
* Air filter blockage: A clogged air filter restricts airflow, leading to a lean fuel mixture, especially under load.
* Vacuum leak: A vacuum leak can cause a lean fuel mixture, resulting in stalling.
* Mass airflow sensor (MAF) malfunction: If the MAF sensor is faulty, the engine won't receive accurate air flow data, causing a poor fuel-air mixture.
Other Potential Causes:
* Throttle position sensor (TPS) problem: A faulty TPS can prevent the engine from receiving the correct signal for throttle position, affecting fuel delivery.
* Dirty throttle body: A dirty throttle body can hinder airflow, leading to stalling.
* Engine control module (ECM) failure: A faulty ECM can disrupt the engine's overall operation, leading to a variety of problems, including stalling.
* Faulty sensors: Sensors like the oxygen sensor, crankshaft position sensor, or camshaft position sensor can malfunction and cause stalling.
Diagnosis and Repair:
* Start with a visual inspection: Check for obvious signs of damage or leaks, especially in the fuel system, air intake, and electrical components.
* Check engine codes: Use a scan tool to read any diagnostic trouble codes (DTCs) stored in the ECM. These codes can provide valuable information about potential issues.
* Test components: Perform individual tests on suspected components, such as the fuel pump, injectors, spark plugs, and sensors.
* Seek professional help: If you're unable to diagnose or repair the problem yourself, consult a qualified mechanic.
Remember: Stalling under load can be a safety hazard. If you're experiencing this problem, it's important to have it diagnosed and repaired as soon as possible.
