1999 Lexus SC 400FACTORY OEM SERVICE PROCEDURE

Firing Order

FIRING ORDER

Application Firing Order
ES300 & RX300 (1) (2) 1-2-3-4-5-6
GS300 & SC300 (3) (4)
GS400, LS400, LX470 & SC400 (1) (5) 1-8-4-3-6-5-7-2
(1) System uses a Distributorless Ignition System (DIS) with ignition coil for each cylinder.
(2) Cylinder No. 1 is front cylinder on right side of engine when viewed from flywheel end of engine. Cylinder No. 2 is front cylinder on left side of engine when viewed from flywheel end of engine. Cylinders No. 1, 3 and 5 are on right side of engine. Cylinders No. 2, 4 and 6 are on left side of engine.

(3) System uses a Distributorless Ignition System (DIS) with 3 ignition coils. Cylinders No. 1 and 6 use same ignition coil. Cylinders No. 2 and 5 use same ignition coil. Cylinders No. 3 and 4 use same ignition coil. Cylinder No. 1 is located at timing belt end of engine and cylinder No. 6 is located at flywheel end of engine.
(4) Firing order is not available from manufacturer.
(5) Cylinder No. 1 is front cylinder on left side of engine when viewed from flywheel end of engine. Cylinder No. 2 is front cylinder on right side of engine when viewed from flywheel end of engine. Cylinders No. 1, 3, 5 and 7 are on left side of engine. Cylinders No. 2, 4, 6 and 8 on right side of engine.
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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.