why does my Volkswagen Tiguan First Generation (2007-2018) have a rough start in the morning

Solution

1. Preparation

• Gather tools and parts: OBD-II scanner, socket set, multimeter, fuel pressure gauge, replacement spark plugs, ignition coils, and air filter.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Battery Inspection and Replacement (if necessary)

• Sub-steps:
  1. Use a multimeter to check battery voltage; it should read around 12.6 volts.
  2. If below 12.4 volts, charge the battery or replace if necessary.
  3. Clean battery terminals with a wire brush and reconnect securely.

3. Fuel System Inspection and Repair

• Sub-steps:
  1. Check the fuel pressure using a fuel pressure gauge; compare it to manufacturer specifications.
  2. If pressure is low, inspect the fuel filter and replace if clogged.
  3. Test the fuel pump operation by listening for it engaging when the ignition is turned on.

4. Ignition System Inspection and Replacement

• Sub-steps:
  1. Remove spark plugs and inspect for wear or fouling; replace if needed.
  2. Test ignition coils with a multimeter to ensure they are within specifications.
  3. Replace any faulty ignition coils.

5. Air Intake System Inspection

• Sub-steps:
  1. Inspect the air filter for dirt and replace if necessary.
  2. Check the intake hoses for cracks or leaks and replace any damaged components.
  3. Ensure the throttle body is clean; clean it if there is excessive carbon buildup.