The 2002 Lexus IS300 uses a 3.0-liter inline-six engine (Toyota 2JZ-GE). The cylinders are numbered from front to back as 1 through 6, and the firing order is 1-5-3-6-2-4.
Cylinder numbering on the 2JZ-GE
For maintenance and diagnostic work, it's important to know the physical cylinder layout. In the IS300, cylinder 1 sits at the front of the engine (closest to the timing components), and cylinder 6 sits at the rear near the firewall. The other cylinders follow sequentially toward the back.
- Front-most cylinder: 1
- Second from the front: 2
- Third from the front: 3
- Fourth from the front: 4
- Fifth from the front: 5
- Rear-most cylinder: 6
Understanding this arrangement helps you identify which cylinder you're working on when inspecting plugs, valves, or seals.
Firing order for the 2JZ-GE
The firing order defines the sequence in which each cylinder receives a spark. For the 2JZ-GE used in the 2002 IS300, the recommended firing sequence is 1-5-3-6-2-4.
- Cylinder 1 fires first
- Cylinder 5 fires second
- Cylinder 3 fires third
- Cylinder 6 fires fourth
- Cylinder 2 fires fifth
- Cylinder 4 fires sixth
When wiring ignition components for a coil-on-plug setup, follow this firing order to ensure proper ignition timing across the six cylinders.
Notes on ignition technology
Modern IS300s use coil-on-plug ignition, with a dedicated coil for each cylinder. There is no traditional distributor. The firing order remains a reference for diagnostics and service procedures, not a driver for distributor timing.
Summary
The IS300's 2JZ-GE inline-six features front-to-back cylinder numbering 1-6 and a firing order of 1-5-3-6-2-4. This knowledge is essential for spark plug replacement, ignition coil servicing, and timing-related diagnostics. Always refer to the factory service manual for exact procedures and torque specs.