what causes a misfire in my Volkswagen Golf MK7 (2015-2019) engine?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shock.
• Ensure the engine is cool before starting any work.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket, dielectric grease.
• Remove the engine cover if applicable.
• Disconnect ignition coils from the harness and remove them using a socket wrench.
• Inspect spark plugs for wear; if damaged, replace them with OEM-spec plugs.
  • Torque Specification: 15 lb-ft for spark plugs.
• Apply dielectric grease to the terminals of the ignition coils before reinstalling.
• Reinstall ignition coils and reconnect the harness.

3. Check and Replace Fuel Injectors

• Tools Required: Fuel pressure gauge, injector removal tool.
• Relieve fuel system pressure by removing the fuel pump fuse and starting the engine until it stalls.
• Disconnect fuel lines carefully to avoid spillage.
• Remove and inspect fuel injectors; clean or replace as necessary.
• Reinstall fuel lines and reconnect the fuel pump fuse.

4. Conduct a Compression Test

• Tools Required: Compression tester.
• Remove spark plugs to facilitate compression testing.
• Insert the compression tester into each cylinder and crank the engine.
• Record the compression readings; compare them to factory specifications.
• If readings are low, further investigate potential internal engine issues.