Possible Causes:
* Fuel Pump: The most common culprit is a failing fuel pump. It may be getting weak or intermittently cutting out. You can test the pump's pressure with a gauge, but a good way to check is to listen for the pump's whirring sound when you turn the key to the "on" position. If you hear a weak or intermittent sound, the pump is likely failing.
* Fuel Filter: A clogged fuel filter can restrict fuel flow and cause sputtering and stalling. It's a relatively inexpensive and easy component to replace.
* Spark Plugs and Wires: Worn or fouled spark plugs and cracked or loose wires can cause misfires and stalling. Inspect the spark plugs and wires for signs of damage or wear.
* Fuel Pressure Regulator: This component controls fuel pressure in the system. A malfunctioning regulator can cause erratic fuel pressure leading to sputtering and stalling.
* Fuel Injectors: Clogged fuel injectors can prevent the proper amount of fuel from reaching the combustion chamber. You can have them professionally cleaned or replaced if necessary.
* Intake Manifold Leak: A vacuum leak in the intake manifold can disrupt the air-fuel mixture and cause sputtering and stalling. Inspect the intake manifold for cracks or loose connections.
* Engine Sensors: Various sensors, including the oxygen sensor, mass airflow sensor, and throttle position sensor, can malfunction and disrupt the engine's fuel and ignition timing, leading to stalling.
Troubleshooting Steps:
1. Check Engine Light: Does the "Check Engine" light come on? If so, scan the engine control module (ECM) for codes. This can give you a starting point for diagnosing the problem.
2. Fuel Pump Test: Listen for the fuel pump whirring when you turn the key to the "on" position. If it's weak or intermittent, you may have a failing fuel pump.
3. Fuel Filter Replacement: Replace the fuel filter even if it's relatively new, as it can become clogged.
4. Spark Plug and Wire Inspection: Visually inspect the spark plugs and wires for wear or damage.
5. Fuel Pressure Gauge Test: Connect a fuel pressure gauge to the fuel rail and check the pressure while the engine is running. This will help determine if the pressure is within spec.
6. Vacuum Leak Inspection: Look for signs of vacuum leaks, such as cracked hoses or loose connections.
7. Sensor Testing: You may need to use a scan tool to check for malfunctioning sensors.
Important Note: If you're not comfortable performing these checks, it's best to take your car to a qualified mechanic for diagnosis and repair.
Safety First: Always exercise caution when working on a vehicle, and disconnect the battery before working on electrical components.
