why does my Ford F-150 12th Generation (2009-2014) idle rough when cold

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the negative battery terminal to ensure safety.

2. Inspect and Replace ECT Sensor (if faulty)

• Sub-steps:
  • Locate the ECT sensor, usually near the thermostat housing.
  • Disconnect the electrical connector from the sensor.
  • Remove the sensor using a socket wrench.
  • Install the new ECT sensor, ensuring it is torqued to manufacturer's specifications (usually around 15-20 ft-lbs).
  • Reconnect the electrical connector.

3. Check and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect all vacuum hoses for cracks or disconnections.
  • Use carburetor cleaner around suspected areas while the engine is running to identify leaks (idle will change if a leak is present).
  • Replace any damaged hoses and ensure all connections are secure.

4. Clean Throttle Body

• Sub-steps:
  • Remove the air intake duct to access the throttle body.
  • Spray throttle body cleaner onto a clean cloth and wipe the throttle body interior, especially around the throttle plate.
  • Open the throttle plate manually to clean the inner edges.
  • Reinstall the air intake duct securely.

5. Inspect and Clean Fuel Injectors

• Sub-steps:
  • Remove the fuel rail (ensure to relieve fuel pressure first).
  • Disconnect the fuel injectors from the wiring harness.
  • Clean the injectors using a fuel injector cleaning kit or replace if necessary.
  • Reinstall all components securely, ensuring proper torque specifications are followed.