my Honda Civic 10th Generation (2016-2021) is hard to start when hot

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool before beginning.
• Disconnect the negative battery terminal for safety.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil cover (if applicable) and unscrew the ignition coils.
• Inspect the spark plugs for wear. Replace them if they show signs of corrosion or excessive wear.
• Reinstall new spark plugs, tightening them to the manufacturer's specified torque (typically around 13-15 lb-ft).
• Reinstall the ignition coils, ensuring they are seated properly.

3. Test and Replace Fuel Components

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail test port.
• Turn the ignition to the "ON" position (do not start the engine) and check the fuel pressure reading; it should be within the manufacturer’s specifications (typically around 40-50 psi).
• If the pressure is low, consider replacing the fuel pump or checking the fuel filter for blockages.

4. Check and Replace Coolant Temperature Sensor

• Tools Required: Multimeter, socket set.
• Locate the coolant temperature sensor, usually near the thermostat housing.
• Disconnect the electrical connector and test the sensor’s resistance using a multimeter; compare the readings to the specifications provided in the service manual.
• If the sensor is faulty, remove it using a socket set and install a new one, ensuring a proper seal with thread sealant if required.

5. Reconnect and Test

• Reconnect the negative battery terminal.
• Start the engine to ensure it runs smoothly, especially when hot.