Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1993 Lexus SC 300 StandardFACTORY 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 NOT
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)* | |||||||
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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:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.