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Ignition Timing

CAUTION: Some tachometers may not be compatible with ignition system. Consult tachometer manufacturer before connecting tachometer to system. DO NOT allow tachometer terminal to become grounded or damage to ignitor and/or coil may exist.
  1. Ensure engine is at normal operating temperature. Connect timing light to No. 6 spark plug wire. Connect tachometer to "IG-" terminal of engine check connector. Set tachometer to 4-cylinder range. See Fig 1.
    Fig 1: Installing Tachometer
    G90B20769Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Install jumper wire between terminals "TE1" and "E1"of engine check connector. See Fig 2. Ensure idle speed is within specification. See IDLE SPEED SPECIFICATIONS TABLE in this article. Note that base timing is within specification. See IGNITION TIMING (Degrees BTDC @ RPM) table in this article. Remove jumper wire from engine check connector.
    Fig 2: Installing Timing Jumper Wire
    G90E20770Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. If ignition timing is not within specifications, check the following: Ensure throttle valve is fully closed. Ensure there is continuity between terminals "IDL" and "E2" of throttle position sensor. Check valve timing.
IGNITION TIMING

Application Base Timing
LS400 8-12 @ 600-700