1993 Lexus LS 400FACTORY OEM SERVICE PROCEDURE

Idle Speed & Ignition Timing

Ensure idle speed and ignition timing are set to specification. See IDLE SPEED SPECIFICATIONS and IGNITION TIMING SPECIFICATIONS tables. For adjustment procedures, see ADJUSTMENTS article.

CAUTION: DO NOTΒ  ground DLC terminal IG-. Damage to ignitor and/or ignition coil may result. Ensure tachometer is compatible with this system before use.
IDLE SPEED SPECIFICATIONS

Application Idle RPM
SC300 With Auto. Trans. 600-700
All Others 650-750
IGNITION TIMING SPECIFICATIONS

Application (1) Base Timing (2) Controlled Timing
ES300 10 @ 650-750 10-20 @ 650-750
GS300 10 @ 650-750 8-12 @ 650-750
LS400 8-12 @ 650-750 (3)*
SC300
Auto. Trans. 10 @ 600-700 9-11 @ 600-700
Man. Trans. 10 @ 650-750 9-11 @ 650-750
SC400 8-12 @ 650-750 (3)*
(1) Jumper wire connected between terminals TE1 and E1 of DLC.
(2) Jumper wire disconnected from DLC.
(3) Information is not available from manufacturer.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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