how to diagnose rough idle on my Ford F-150 13th Generation (2015-2020)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is off.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Replace Spark Plugs

• Steps:
  1. Remove the engine cover (if applicable) using a socket set.
  2. Disconnect the ignition coils by unplugging the electrical connectors.
  3. Remove the ignition coils using a socket wrench.
  4. Use a spark plug socket to remove the old spark plugs.
  5. Install new spark plugs, ensuring they are gapped correctly per manufacturer specifications (usually around 0.042-0.046 inches).
  6. Reinstall the ignition coils and reconnect the electrical connectors.
  7. Replace the engine cover and reconnect the negative battery terminal.

3. Clean Throttle Body

• Steps:
  1. Remove the air intake duct connected to the throttle body.
  2. Use throttle body cleaner and a soft cloth to gently clean the throttle plate and surrounding area.
  3. Ensure the throttle plate opens and closes freely without obstruction.
  4. Reconnect the air intake duct securely.

4. Inspect and Replace Fuel Filter (if applicable)

• Steps:
  1. Locate the fuel filter; refer to the vehicle's service manual for the exact location.
  2. Relieve fuel pressure from the system by removing the fuel pump relay and starting the engine until it stalls.
  3. Disconnect fuel lines carefully using a fuel line disconnect tool.
  4. Remove the old fuel filter and install the new filter, ensuring the flow direction is correct.
  5. Reconnect the fuel lines and reinstall the fuel pump relay.