Ignition Timing: Adjustments

NOTE: Timing specifications are listed on the Vehicle Emissions Control Information label under the hood. Always follow the Vehicle Emissions Control Information label procedures first before using the following procedure.

Timing Mark 4.3L (M/L):

PROCEDURE:

Set timing under the following conditions:

^ Normal operating temperature.
^ Air cleaner installed.
^ A/C "OFF".
^ Transmission in neutral.
^ Disconnect SET TIMING connector (tan/black wire) located in harness close to distributor. DO NOT disconnect 4 wire connector at distributor.

Connect timing light and adjust as necessary by loosening hold down bolt and rotating distributor. For specification, refer to SPECIFICATIONS/TIMING MARKS. Tighten hold down and recheck the timing. Stop the engine and connect SET TIMING connector. Clear ECM trouble code by disconnecting ECM power source. With engine at operating temperature, drive vehicle at part throttle with moderate acceleration and decelerate to idle condition. This will "teach" the ECM/VCM and return the engine to normal performance.