How to Adjust the Timing in a Toyota Corolla

Adjusting the timing on a Toyota Corolla is required periodically to ensure proper operation, fuel efficiency and lower emissions. This guide covers Toyota Corolla models with distributed ignition systems built after 1977. Toyota Corolla models with a distributor-less ignition system require adjustment by a professional. Changing the timing on a Toyota Corolla requires special tools and a clear understanding of engine mechanics.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• Timing light
• Wrenches
• Jumper wire

1. Start the engine, allowing it to reach normal operating temperature. Turn the engine off and identify the crankshaft pulley at the bottom front of the engine. Clean off any dirt or grime to expose the timing marks.

2. Connect the timing light to the battery if necessary and then to the number one ignition wire located at the far left on "4" series engines and on the far right on "2" and "3" series engines. Start the car and allow it to idle for 2 minutes.

3. Point the timing light at the crankshaft pulley to determine the amount of adjustment needed. Loosen the distributor mounting bolts and turn the distributor slowly until the timing mark on the crankshaft pulley matches the middle line on the timing light.

4. Tighten the distributor mounting bolts and recheck the timing to ensure nothing moved. Turn off the engine and remove the timing light. Reconnect the number one ignition wire.

Tips & Warnings

• Always work with a running engine in a well ventilated area.
• Keep hair, tools and wires away from the cooling fan at all times.

Resources

• Timing lights and accessories

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