my BMW 3 Series F30/F31 (2012-2019) has a rough idle and stalls

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical issues while working.
• Ensure the engine is cool before starting any work.

2. Address Faulty Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover if present.
• Disconnect the ignition coils by unplugging their electrical connectors.
• Remove the ignition coils from the spark plugs by unscrewing them.
• Inspect spark plugs for wear or damage; replace if necessary.
• Reinstall the ignition coils and ensure they are securely connected.
• Reconnect the battery.

3. Clean or Replace Throttle Body

• Tools Required: Throttle body cleaner, soft cloth, socket set.
• Remove the intake duct connected to the throttle body.
• Use throttle body cleaner to remove carbon buildup from the throttle body.
• Clean the throttle plate and surrounding areas thoroughly.
• Reinstall the intake duct and ensure all clamps are tight.

4. Check and Clean MAF Sensor

• Tools Required: MAF cleaner, screwdriver.
• Locate the MAF sensor in the intake system.
• Unplug the electrical connector from the MAF sensor.
• Remove the MAF sensor from its housing using the screwdriver.
• Spray MAF cleaner onto the sensor elements and allow it to dry completely.
• Reinstall the MAF sensor and reconnect the electrical connector.

5. Inspect Fuel System

• Tools Required: Fuel pressure gauge, wrench set.
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "On" position (do not start the engine) and check the pressure reading against manufacturer specifications.
• If pressure is low, inspect the fuel pump, fuel filter, and fuel lines for blockage or failure.