Ignition Timing: Adjustments

Timing Mark:

Timing specifications for each engine are listed on the underhood Vehicle Emissions Control Information label in the engine compartment.

The 4.9L engine incorporates a magnetic timing probe hole for use with special electronic timing equipment. Refer to the manufacture's instructions for the use of this equipment.

Malfunction codes may be set during ignition timing. Enter diagnostics and clear codes if this occurs.

1. With ignition "OFF," connect the pickup lead of timing light to the number one spark plug. Use a jumper lead between the wire and plug or an inductive type pickup.

2. With engine at normal operating temperature and A/C "OFF," Remove air cleaner housing upper.

3. Jumper pins A & B at the DLC connector while not in diagnostic display. "SET TIMING MODE" message will be displayed on the Climate Control Driver Information Center.

4. Start engine and aim the timing light at the timing mark. The line on the pulley will line up at the timing mark. If a change is necessary, loosen the distributor hold-down clamp nut with J 29791. While observing the mark with the timing light, slightly rotate the distributor until the line indicates the correct timing. Tighten the hold-down nut and recheck the timing.

5. Set base timing at 10 degrees (BTDC) at any speed less then 800 RPM.

6. Turn off engine and remove timing light.

7. Remove the jumper from DLC connector and install air cleaner housing upper.