why is my BMW 3 Series F30/F31 (2012-2019) stalling at traffic lights

Solution

1. Preparation

• Tools Required: OBD-II scanner, fuel pressure gauge, socket set, cleaning supplies
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before beginning work.

2. Address Error Codes

• Reconnect the OBD-II scanner and clear any stored trouble codes.
• Note any persistent codes for further diagnosis.

3. Inspect and Clean Components

A. Air Intake System

• Remove the air intake duct.
• Inspect for cracks or leaks; replace if necessary.
• Clean the MAF sensor using MAF cleaner; let it dry completely before reinstallation.

B. Throttle Body

• Remove the throttle body from the intake manifold.
• Use throttle body cleaner and a soft cloth to remove carbon buildup.
• Reinstall the throttle body and ensure proper sealing.

4. Test and Replace Fuel Components

A. Fuel Pressure

• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and check the fuel pressure; it should be within the manufacturer’s specifications.
• If pressure is low, inspect and potentially replace the fuel pump or fuel filter.

B. Idle Air Control Valve

• Remove the IAC valve from the intake.
• Clean it with electrical cleaner; if malfunctioning, replace it with a new unit.

5. Final Assembly

• Reinstall all components in reverse order of removal.
• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.