why does my BMW 3 Series G20/G21 (2019-2024) engine hesitate when accelerating?

Solution

1. Preparation

• Gather tools and materials needed for the repair.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Clean or Replace Throttle Body

• Sub-steps:
  1. Remove the air intake duct connected to the throttle body using a socket set.
  2. Disconnect the throttle body electrical connector.
  3. Remove the throttle body mounting screws and carefully detach the unit.
  4. Clean the throttle body with throttle body cleaner and a soft cloth, ensuring all carbon deposits are removed.
  5. Reinstall the throttle body, tightening screws to the manufacturer's torque specifications (typically around 10 Nm).
  6. Reconnect the electrical connector and reattach the air intake duct.

3. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Remove the engine cover to access the spark plugs.
  2. Disconnect the ignition coils from the spark plugs.
  3. Use a spark plug socket to remove the old spark plugs.
  4. Inspect the old plugs for wear and gap specifications; replace if necessary.
  5. Install new spark plugs, ensuring they are gapped to the manufacturer's specifications (typically around 0.7-0.8 mm).
  6. Reinstall the ignition coils and engine cover.

4. Check Fuel Pressure

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect a fuel pressure gauge to the test port.
  3. Turn the ignition to the "ON" position (without starting the engine) to check for fuel pressure.
  4. Compare the pressure reading to the manufacturer's specifications (typically around 50-60 psi).
  5. If pressure is low, inspect the fuel pump and replace if necessary.