why does my BMW 3 Series jerk when accelerating

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent any electrical issues during repair.

2. Inspect and Replace Ignition Components

• Sub-steps:
  1. Remove the engine cover (if applicable) using a socket set.
  2. Unplug the ignition coils from the spark plugs.
  3. Remove the spark plugs using a spark plug socket and inspect for wear or fouling.
  4. Replace spark plugs with OEM recommended types, ensuring proper torque (typically 15-20 Nm).
  5. Reinstall the ignition coils and reconnect electrical connectors.

3. Fuel System Inspection

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position (do not start) and check the pressure against manufacturer specifications (typically 50-60 psi).
  3. If pressure is low, check the fuel filter and replace if clogged.
  4. Inspect the fuel pump for proper operation and replace if necessary.

4. Throttle Body Cleaning

• Sub-steps:
  1. Remove the air intake duct connected to the throttle body.
  2. Use throttle body cleaner and a soft brush to clean the throttle plate and surrounding area.
  3. Reassemble the intake duct and secure all clamps and connections.

5. Transmission Fluid Check (if applicable)

• Sub-steps:
  1. Locate the transmission dipstick and check the fluid level.
  2. Inspect the fluid condition; if it appears dark or burnt, consider a fluid change.
  3. If changing fluid, drain the transmission fluid and replace with manufacturer-approved fluid, ensuring to fill to the correct level.