Ignition Timing

CAUTION: Some tachometers may not be compatible with ignition system. Consult tachometer manufacturer before connecting tachometer to system. To avoid possible damage to ignitor and/or coil, DO NOT allow tachometer terminal to become grounded.

Warm engine to normal operating temperature. Shut engine off. Connect timing light. Connect tachometer to proper terminals of engine check connector. See Fig 1-Fig 3 .
Install jumper wire between proper terminals of engine check connector. See Fig 4-Fig 6 . Start engine and ensure idle speed is within specification. Ensure base timing is within specification with engine at specified RPM. See the 6-CYLINDER IGNITION TIMING (DEGREES BTDC @ RPM) table.
NOTE: Timing marks are on front cover on all models except Land Cruiser. On Land Cruiser, timing mark on flywheel must be aligned with pointer positioned above starter motor. See Fig 7.
On Supra turbo models with Distributorless Ignition System (DIS), adjust ignition timing by rotating cam position sensor, located on rear of cylinder head. On all other models, adjust timing by rotating the distributor.
Remove jumper wire from engine check connector and ensure advance timing is within specification. See the 6-CYLINDER IGNITION TIMING (DEGREES BTDC @ RPM) table. Tighten distributor hold-down bolt or cam position sensor bolt. See TORQUE SPECIFICATIONS .