my Toyota Corolla E170 (2013-2019) has a rough start in the morning what's the issue

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to ensure safety during the repair process.

2. Battery Inspection and Replacement (if needed)

1. Check Battery Voltage
   • Use a multimeter to measure the battery voltage. It should read around 12.6 volts when fully charged.
2. Clean Battery Connections
   • Remove any corrosion from the battery terminals using a wire brush.
3. Replace Battery (if needed)
   • If the voltage is low or the battery is over three years old, consider replacing it with a new one.
   • Ensure the new battery is securely connected.

3. Fuel System Inspection

1. Check Fuel Pressure
   • Connect a fuel pressure gauge to the fuel rail.
   • Turn the ignition to the "ON" position without starting the engine to check the pressure; it should be within the manufacturer's specifications (typically 30-40 psi).
2. Replace Fuel Filter (if necessary)
   • If the pressure is low, consider replacing the fuel filter.
   • Locate the filter, relieve fuel pressure, and disconnect the lines before replacing it.

4. Spark Plug and Ignition Coil Replacement

1. Remove Spark Plugs
   • Use a socket wrench to remove the spark plugs, inspecting them for wear or fouling.
2. Replace Spark Plugs
   • Install new spark plugs, ensuring they are gapped correctly according to manufacturer specifications (usually around 0.044 inches).
3. Test and Replace Ignition Coils (if necessary)
   • Use a multimeter to test each ignition coil; if any do not meet specifications, replace them.

5. Air Intake Inspection

1. Inspect Air Filter
   • Remove the air filter and inspect for dirt or blockage.
   • Replace the air filter if it is dirty.
2. Check the Intake Manifold
   • Inspect for any vacuum leaks that may affect air-fuel mixture.