how to troubleshoot my Toyota RAV4 Fifth Generation (2019-present) engine misfire

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a flat surface, and the engine is cool.
• Disconnect the battery to ensure safety while working on electrical components.

2. Replace Spark Plugs

• Tools Required: Spark plug socket, torque wrench, ratchet.
• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector for each cylinder.
  3. Remove the ignition coil using the socket.
  4. Remove the old spark plug using the spark plug socket.
  5. Inspect the new spark plug for proper gap according to manufacturer's specifications.
  6. Install the new spark plug and torque to the manufacturer’s specification (usually around 13-15 lb-ft).
  7. Reinstall the ignition coil and reconnect the connector.

3. Inspect and Replace Ignition Coils (if necessary)

• Tools Required: Ratchet, socket set.
• Sub-steps:
  1. If the ignition coils are damaged or faulty, remove them by unscrewing the mounting bolts.
  2. Install the new ignition coils, ensuring they are seated correctly.
  3. Reconnect the electrical connectors.

4. Test Fuel Injectors

• Tools Required: Fuel pressure gauge, injector cleaning kit.
• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position (do not start the engine) to check the fuel pressure.
  3. If the pressure is below specifications, inspect the fuel pump and filter.
  4. If necessary, clean or replace faulty fuel injectors.

5. Check for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• Sub-steps:
  1. Inspect all vacuum hoses for cracks or disconnections.
  2. Use a smoke machine to locate leaks; if unavailable, spray carburetor cleaner around suspected areas and listen for RPM changes.
  3. Replace any damaged hoses.