what causes my Volkswagen Golf MK7 (2015-2019) to stall when coming to a stop?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during the repair.
• Allow the vehicle to cool down if the engine has been running recently.

2. Clean the Throttle Body

• Tools Required: Throttle body cleaner, soft-bristle brush, microfiber cloth, socket set.
• Remove the air intake duct connected to the throttle body.
• Spray throttle body cleaner into the throttle body and scrub with a soft-bristle brush.
• Wipe clean with a microfiber cloth and ensure no cleaner residue remains.
• Reinstall the air intake duct securely.

3. Inspect and Clean the Idle Air Control Valve (IAC)

• Tools Required: Socket set, screwdriver, cleaning solvent.
• Locate the IAC valve, typically near the throttle body.
• Disconnect the electrical connector and remove the IAC valve from the intake manifold.
• Clean the valve with solvent and check for proper operation.
• Reinstall the IAC valve, ensuring a secure fit and reconnect the electrical connector.

4. Test Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Locate the fuel pressure test port on the fuel rail.
• Connect the fuel pressure gauge and turn the ignition to the "on" position without starting the engine.
• Check the pressure reading against manufacturer specifications (typically around 50-60 psi).
• If the pressure is low, inspect the fuel pump and filter for issues.

5. Inspect Vacuum Lines

• Tools Required: Visual inspection tools (flashlight).
• Visually inspect all vacuum lines connected to the intake manifold and throttle body for cracks or disconnections.
• Replace any damaged vacuum lines as necessary to ensure a proper seal.