why does my Volkswagen Tiguan struggle to start after sitting for a few days?

Solution

1. Battery Inspection and Replacement

• Sub-step 1: Disconnect the negative battery terminal to prevent electrical shorts.
• Sub-step 2: Remove the battery from the vehicle using a socket set.
• Sub-step 3: Clean the battery terminals with a wire brush and apply a protective coating.
• Sub-step 4: If the battery voltage is low (below 12.4 volts), consider replacing it with a new, fully charged battery.

2. Charging System Check

• Sub-step 1: Reconnect the battery and start the engine.
• Sub-step 2: Measure the voltage across the battery terminals with the engine running; it should be around 13.7 to 14.7 volts.
• Sub-step 3: If the voltage is low, inspect the alternator and replace it if necessary.

3. Fuel System Inspection

• Sub-step 1: If no fuel pump noise is heard, check the fuel pump relay and replace it if faulty.
• Sub-step 2: Test the fuel pump operation using a fuel pressure gauge; it should meet the specifications listed in the service manual.
• Sub-step 3: If the fuel pump is not operational, it will need replacement.

4. Electrical System Check

• Sub-step 1: Inspect all fuses related to the starting and fuel systems and replace any blown fuses.
• Sub-step 2: Check the ignition switch for proper operation; replace if faulty.