my Toyota Corolla E210 (2019-2024) has a rough start in the morning, what’s wrong?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to ensure safety while working on electrical components.

2. Replace Spark Plugs

1. Remove the ignition coil cover (if applicable) by unscrewing any bolts.
2. Disconnect the ignition coils by unplugging the electrical connectors.
3. Remove the spark plugs using a socket wrench and spark plug socket.
4. Inspect the old spark plugs for wear and gaps, and compare with specifications. Replace if necessary.
5. Install new spark plugs, ensuring the proper gap is set (usually 0.043 inches for Corolla).
6. Reconnect the ignition coils and cover, securing them with bolts.

3. Test Fuel System

1. Locate the fuel pressure test port, typically on the fuel rail.
2. Attach a fuel pressure gauge to the test port and turn the ignition to the "ON" position without starting the engine.
3. Check the pressure reading against manufacturer specifications (usually around 43-50 psi).
4. If pressure is low, inspect and replace the fuel filter if it is clogged, or consider fuel pump replacement.

4. Inspect Air Filter

1. Open the air filter housing and remove the air filter.
2. Examine the air filter for dirt and obstructions. Replace if it is excessively dirty or damaged.
3. Reinstall the air filter and close the housing securely.