Ignition Timing

NOTE: On vehicles equipped with automatic transmission, place selector lever in "D" position and block the wheels.

Warm engine to normal operating temperature. Connect a tachometer, then connect timing light to leading (lower) spark plug of front rotor. Start engine and run at idle speed.
Check ignition timing and rotate distributor to correct if necessary. Tighten distributor lock nut and recheck timing.
Connect timing light to trailing (upper) plug of front rotor. Start engine and check timing. If not correct, loosen vacuum unit attaching screws. Move vacuum unit in or out to adjust trailing timing. Remove test equipment.

Fig 1: Connecting Timing Light (Check Leading Plug Timing First)

Fig 2: Ignition Timing Mark Location

IGNITION TIMING (DEGREES ATDC @ RPM)

Application	Timing
Leading	TDC @ 750
Trailing	20 @ 750