why does my Toyota Corolla E140 (2006-2013) engine misfire at idle

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shock.

2. Replace Spark Plugs

• Remove the ignition coils by unscrewing the retaining bolts and gently pulling them off the spark plugs.
• Use a spark plug socket to remove the old spark plugs.
• Inspect the spark plug gap and replace with new plugs if outside manufacturer specifications (typically 0.043 inches for this model).
• Install new spark plugs and torque them to 13 lb-ft (18 Nm).

3. Inspect and Replace Ignition Coils

• If any ignition coils were found faulty, replace them one at a time.
• Disconnect the electrical connector and unscrew the coil from the engine.
• Install the new ignition coil and reconnect the wiring harness.

4. Clean or Replace Fuel Injectors

• If fuel injectors are clogged, use a fuel injector cleaner or replace them.
• For cleaning, remove the fuel rail and injectors, and use a professional cleaning kit.
• If replacing, ensure new injectors are compatible and install following manufacturer specifications.

5. Check for Vacuum Leaks

• Inspect all vacuum hoses for cracks or disconnections.
• Replace any damaged hoses and ensure tight connections.
• Re-test the engine’s vacuum after repairs.