my Ford Explorer Fifth Generation (2011-2019) keeps misfiring, what could be wrong?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil by unbolting and disconnecting the electrical connector.
• Use the spark plug socket to remove old spark plugs.
• Inspect the gap on the new spark plugs and adjust to manufacturer's specification.
• Install new spark plugs and torque to the manufacturer's specification (typically around 13-15 ft-lbs).
• Reinstall ignition coils securely.

3. Inspect and Replace Ignition Coils (if necessary)

• Tools Required: Socket set, torque wrench
• Remove the bolts securing the ignition coil.
• Disconnect the electrical connectors from each ignition coil.
• Replace with new ignition coils, ensuring they are seated correctly.
• Torque the ignition coil bolts to manufacturer specifications (usually around 7-10 ft-lbs).

4. Check and Replace Fuel Injectors (if necessary)

• Tools Required: Fuel injector puller, socket set, torque wrench
• Relieve fuel system pressure by removing the fuel pump fuse and starting the engine until it stalls.
• Disconnect the fuel lines from the injectors and remove the hold-down bolts.
• Replace any faulty injectors with new ones, ensuring they are properly seated and torqued according to specifications.

5. Verify Fuel Pressure

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail test port.
• Turn the ignition to the "ON" position without starting the engine to check for proper fuel pressure (typically around 60-65 psi).
• If pressure is low, inspect the fuel pump and filter for issues.