why does my Volkswagen Golf MK7 (2015-2019) have a rough start in the morning?

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the engine is cool.
• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Battery Inspection

• Sub-steps:
  1. Remove the battery terminals, starting with the negative terminal.
  2. Use a multimeter to measure the battery voltage; it should read around 12.6 volts when fully charged.
  3. Clean any corrosion from terminals using a wire brush.
  4. Reconnect the battery terminals, ensuring a tight connection.

3. Fuel System Check

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Attach a fuel pressure gauge and turn the ignition to the "ON" position without starting the engine.
  3. Verify that the pressure matches specifications (typically around 50-60 psi for this model).
  4. If pressure is low, check the fuel pump and filter for issues; replace if necessary.

4. Spark Plug and Ignition Coil Replacement

• Sub-steps:
  1. Remove the engine cover if equipped to access ignition components.
  2. Disconnect the ignition coil connectors and remove the bolts securing the coils.
  3. Carefully pull out the ignition coils and inspect them for cracks or wear.
  4. Remove the spark plugs using a spark plug socket and inspect for wear or carbon buildup.
  5. Replace with new spark plugs (OEM recommended) and reinstall the ignition coils.

5. Check for Vacuum Leaks

• Sub-steps:
  1. Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Use a smoke machine or carb cleaner to detect leaks while the engine is running.
  3. Replace any damaged hoses or gaskets as necessary.