This write up will show you how to set base ignition timing using an adjustable timing light. This applies to all 1G 4G63 engines INCLUDING non turboed 4G63’s, with an adjustable 1G CAS (Cam Angle Sensor).

Tools Needed:
*3/8″ drive ratchet
*12mm socket, 3/8″ drive
*3″ extension for a 3/8″ drive
*Flat head screwdriver
*Adjustable Timing Light

Step 1: First, start your car and let it run for approximately 5 minutes or till the engine is at normal operating temperature. Turn off ALL accessories (A/C, heater, lights, radio, etc.)

Step 2: Remove the upper timing belt cover that protects the cam gears (if you have an upper timing belt cover).

Step 3:
You will need to ground the ignition timing plug located on the firewall. This will override the ECU and make the car idle at 800RPMS.

Step 4: Hook up your timing light power leads to the battery terminals. Red to positive. Black to ground. Then, hook the timing light pickup to the number 1 spark plug wire (spark plug wire on the driver side/timing belt side end).

Step 5: Unbolt the CAS. There are (2) 12mm nuts that hold the CAS in place. Loosen these until you can rotate the CAS. Note- you DO NOT want to remove the nuts, just loosen them a bit. Only one nut is visible in the picture below.


Step 6: Set your adjustable timing light to 5* advanced. Start the engine, then point the timing light at the cam gears.

Step 7:
Turn the CAS until the timing marks on the cam gears line up perfectly.


Step 8: Tighten the nuts back up on your CAS.

Step 9: Check your timing again to make sure the CAS did not rotate when you tightened it up.

Step 10: Un-ground the timing plug on the firewall.

And you’re done! That was easy right?

NOTE- You should shine the timing light at the crank pulley if you have a lower timing belt cover. If not, use the cam gears as shown above.

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