Base timing for distributorless ignition engines is set at the factory at 10 degrees Before Top Dead Center (BTDC) and is not adjustable.
Distributor Ignition System
- Before servicing the vehicle, refer to the precautions in the beginning of this section.
- Place transmission in P . The air conditioning and heater controls should be in the OFF position.
- Connect a suitable inductive timing light and a tachometer according to the manufacturer's instructions.
- Disengage the single wire inline spout connector or remove the shorting bar from the double wire spout connector.
Start the engine and bring it up to normal operating temperature.
NOTETo set timing correctly, a remote starter should not be used. Use the ignition key only to start the vehicle. Disconnecting the start wire at the starter relay will cause the Ignition Control (ICM) module to revert to "start mode timing" after the vehicle is started. Reconnecting the start wire after the vehicle is running will not correct the timing.
- With the engine running at the timing rpm specified, check the initial timing by aiming the timing light at the timing marks and pointer. Refer to the underhood Vehicle Emission Control Information (VECI) label for specific specifications.
- If the marks do not align, shut the engine OFF and loosen the distributor hold-down clamp bolt. Start the engine, and while watching the timing marks with the timing light, turn the distributor until the marks are correctly aligned. Shut the engine OFF , then tighten the distributor hold-down clamp bolt to 17-25 ft. lbs. (23-34 Nm).
- Reattach the single wire inline spout connector or reinstall the shorting bar on the double wire spout connector. Check the timing advance to verify the distributor is advancing beyond the initial setting.
- Remove the timing light and tachometer.
Distributorless Ignition System
Base timing for 5.4L and 6.8L distributorless ignition engines is set at the factory at 10 degrees Before Top Dead Center (BTDC) and is not adjustable.