my Volkswagen Golf MK7 (2015-2019) has a hard starting issue, what should I check?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is off.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Check Battery and Connections

• Inspect battery terminals for corrosion and clean them with a wire brush if necessary.
• Use a multimeter to test the battery voltage; it should be above 12.4 volts.
• If the voltage is low, recharge or replace the battery as needed.

3. Fuel System Inspection

• Fuel Pump Test:
  • Locate the fuel pump relay and activate it to check for noise.
  • Use a fuel pressure gauge to measure fuel pressure at the rail; it should typically be around 50-60 psi.
• Replace Fuel Filter:
  • If fuel pressure is low, check and replace the fuel filter if clogged.

4. Ignition System Check

• Inspect Spark Plugs:
  • Remove spark plugs and inspect for wear or fouling; replace if necessary.
• Test Ignition Coils:
  • Use an ohmmeter to check the resistance of each ignition coil; replace any that are out of specification.

5. Crankshaft Position Sensor

• Disconnect the electrical connector from the crankshaft position sensor.
• Use a multimeter to check the sensor’s resistance; it should be within manufacturer specifications.
• Replace the sensor if it is faulty.