my Ford F-150 14th Generation (2021-2024) engine is idling rough when cold

Solution

1. Preparation

• Gather tools and parts: OBD-II scanner, fuel pressure gauge, socket set, cleaning supplies, new spark plugs, throttle body cleaner.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Scan for Error Codes

• Connect the OBD-II scanner to the vehicle's diagnostic port.
• Turn the ignition to the "ON" position without starting the engine.
• Record any trouble codes and refer to the service manual for diagnosis.

3. Inspect and Clean the Air Intake System

• Remove the air filter and inspect for dirt and obstructions.
• Clean the air intake duct using a soft cloth.
• Replace the air filter if it appears dirty.

4. Check Fuel Pressure

• Connect the fuel pressure gauge to the fuel rail test port.
• Start the engine and observe the fuel pressure readings; it should match the manufacturer's specifications (typically between 50-70 PSI).
• If fuel pressure is low, inspect the fuel pump and fuel filter.

5. Examine and Replace Spark Plugs

• Remove the spark plug wires or ignition coils.
• Use a socket set to remove the spark plugs.
• Inspect for signs of wear or fouling; replace with OEM-spec spark plugs if necessary.
• Reinstall spark plugs and reconnect wires or coils.

6. Test Coolant Temperature Sensor

• Locate the coolant temperature sensor and disconnect the electrical connector.
• Using a multimeter, measure the resistance across the terminals.
• Compare readings with the specifications provided in the service manual. Replace the sensor if readings are out of range.

7. Clean Throttle Body

• Remove the throttle body from the intake manifold (if applicable).
• Use throttle body cleaner and a soft brush to clean the interior surfaces.
• Reinstall the throttle body and ensure all gaskets are properly seated.