how to fix rough acceleration in my BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before starting.

2. Inspect and Replace Ignition Components

• Sub-steps:
  1. Remove engine cover (if applicable) to access ignition coils.
  2. Unplug each ignition coil connector and remove the bolts securing the coils.
  3. Extract each coil and inspect for cracks or damage.
  4. If spark plugs are worn, remove them using a socket wrench. Replace with new spark plugs (ensure correct gap).
  5. Install new ignition coils and reconnect the connectors, securing with bolts.

3. Check and Adjust Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position without starting the engine to check the fuel pressure.
  3. If pressure is below specifications, replace the fuel filter and inspect the fuel pump.
  4. Reattach the fuel pressure gauge and verify pressure during acceleration.

4. Clean Throttle Body

• Sub-steps:
  1. Remove the intake duct by loosening clamps and disconnecting any sensors.
  2. Unbolt the throttle body from the intake manifold.
  3. Use throttle body cleaner and a soft cloth to clean the throttle plate and bore.
  4. Reinstall the throttle body and intake duct, ensuring all connections are secure.

5. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks or disconnections.
  2. Replace any damaged hoses.
  3. Use a smoke machine to identify leaks in the intake system if necessary.