my Volkswagen Golf MK5 (2004-2008) stalls at red lights what's wrong

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.
• Allow the engine to cool if recently run.

2. Inspect and Clean Throttle Body

• Tools Required: Throttle body cleaner, soft brush, cleaning cloth, socket set.
• Remove the air intake duct connected to the throttle body.
• Spray throttle body cleaner inside the throttle body while opening the throttle plate manually.
• Use a soft brush to clean any stubborn carbon deposits.
• Wipe the area with a clean cloth, ensuring no debris falls into the intake.

3. Check and Replace Spark Plugs

• Tools Required: Spark plug socket, torque wrench, dielectric grease.
• Remove the ignition coils by unbolting them and disconnecting the electrical connectors.
• Remove the spark plugs using a spark plug socket.
• Inspect the spark plugs for wear or fouling and replace if necessary.
• Apply dielectric grease to the new spark plug threads and install them to the specified torque (usually 15-20 lb-ft).
• Reinstall the ignition coils.

4. Test and Adjust Fuel Pressure

• 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 pressure reading.
• It should match the manufacturer’s specifications (typically 40-60 psi for many models).
• If the pressure is low, consider checking or replacing the fuel pump or fuel filter.

5. Reconnect Battery and Test

• Reconnect the battery terminals.
• Start the engine and allow it to reach operating temperature.
• Check for smooth idle and monitor for any warning lights.