why does my Honda Civic 10th Generation (2016-2021) have a rough start

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, fuel pressure gauge, basic hand tools.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool down if it has been running.

2. Battery Inspection and Replacement

• Check the battery voltage using a multimeter; it should be above 12.4 volts.
• If the battery is below this voltage, replace it:
  1. Remove the negative terminal first, followed by the positive terminal.
  2. Remove any securing brackets and lift the battery out.
  3. Install the new battery by reversing the removal process and tightening connections securely.

3. Fuel System Inspection

• Tools Required: Fuel pressure gauge.
• Check the fuel pressure:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect the fuel pressure gauge and turn the ignition to the "ON" position without starting the engine.
  3. Record the pressure reading; it should meet manufacturer specifications (typically 40-50 psi).
  4. If low, inspect the fuel pump and replace if necessary.

4. Ignition System Inspection

• Tools Required: Socket set, spark plug socket.
• Check the spark plugs:
  1. Remove the ignition coil by unscrewing the bolts and gently pulling it out.
  2. Remove the spark plug using a spark plug socket.
  3. Inspect the spark plug for wear and replace if necessary.
  4. Reinstall the spark plugs and ignition coils securely.

5. Air Filter and Intake Inspection

• Tools Required: Basic hand tools.
• Inspect and replace the air filter:
  1. Open the air filter housing by unscrewing the clips/bolts.
  2. Remove the old air filter and check for dirt or damage.
  3. Install a new air filter, ensuring it fits snugly in place.
  4. Reassemble the air filter housing.