why does my Genesis G70 have a rough engine idle when warm

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Remove the engine cover if necessary.
  2. Disconnect the ignition coils from the spark plugs.
  3. Use a socket wrench to remove the old spark plugs.
  4. Inspect the spark plug condition; replace if worn or fouled.
  5. Install new spark plugs, torque to manufacturer specifications (typically 13-15 lb-ft).
  6. Reconnect the ignition coils.

3. Clean or Replace Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail along with the fuel injectors.
  2. Clean the injectors using a specialized fuel injector cleaning solution or replace them if necessary.
  3. Reinstall the injectors and fuel rail, ensuring proper sealing and torque.

4. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses and connections for cracks or disconnections.
  2. Use a smoke machine or carburetor cleaner to identify leaks while the engine is running.
  3. Replace any damaged hoses and ensure all connections are secure.

5. Test and Replace the Idle Air Control Valve (IAC)

• Sub-steps:
  1. Locate the IAC valve typically found on the throttle body.
  2. Disconnect the electrical connector and remove the IAC valve.
  3. Clean the valve with throttle body cleaner or replace it if malfunctioning.
  4. Reinstall the IAC valve and reconnect the electrical connector.

6. Measure Fuel Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition to the "ON" position without starting the engine and check the pressure.
  3. Start the engine and monitor the pressure; it should remain within manufacturer specifications.
  4. If pressure is low, check the fuel pump and regulator for faults.