Applications Toyota 3S-GTE
Draft. Trigger offset has not been confirmed on a running Race Core install. Pins marked TBD are unknown — do not guess them. A wrong decoder or firing order can destroy the engine.
Toyota 3S-GTE
Celica GT-Four, MR2 Turbo, Caldina GT-T. Four generations of trigger and ignition. Gen 3 ST205 is the common standalone target: wasted-spark, MAP-friendly, 36-2 on many aftermarket dampers.
Recommended: Race Core F7 or Core EFI V4. Four sequential injectors and four logic coils. Factory distributor (gen 2) can stay on Ign 1 with an igniter; gen 3 wasted-spark uses Ign 1–2; gen 4 COP uses Ign 1–4.
- Cylinders: 4
- Displacement: 1998 cc
- Firing order: 1-3-4-2
- Orientation: Cylinder 1 timing-belt / front of the engine. Transverse in Celica, MR2, Caldina, ST215 rally.
Variants
| Variant | Years | Trigger | Notes |
|---|---|---|---|
| Gen 2 ST185 / SW20 | 1990–1993 | NE 24+1 / distributor | Distributor ignition. AFM. Convert trigger or keep dizzy + aftermarket crank. |
| Gen 3 ST205 | 1994–1999 | Crank + cam, wasted spark | Best standalone starting point. CT20B/CT26. 8.5:1. Cable throttle, ISC. |
| Gen 4 ST215 / ST246 | 1997–2007 | 36-2 class crank + cam, VVT-i on some | COP, sequential, VVT-i intake on later Caldina. |
Recommended pin assignment (Race Core F7)
| Pin | TunerStudio | Function |
|---|---|---|
| B5 / B13 | VR 1+ / VR 1− | Crank VR |
| B4 / B12 | VR 2+ / VR 2− | Cam VR |
| B10 | Digital 1 | Crank Hall |
| B1 | Digital 2 | Cam Hall |
| A3 | Lowside 1 | Injector cylinder 1 |
| A15 | Lowside 2 | Injector cylinder 2 |
| A4 | Lowside 3 | Injector cylinder 3 |
| A16 | Lowside 4 | Injector cylinder 4 |
| A35 | Ign 1 | Cyl 1 logic coil |
| A34 | Ign 2 | Cyl 2 logic coil |
| A22 | Ign 3 | Cyl 3 logic coil |
| A33 | Ign 4 | Cyl 4 logic coil |
| C20 | Analog Temp 3 | CLT |
| C30 | Analog Temp 2 | IAT |
| C13 | Analog Volt 1 | MAP 0–5 V |
| C24 | Analog Volt 2 | TPS 1 |
| C34 | Knock 1 | Knock bank 1 |
| A20 | Lowside 10 | Fuel-pump relay coil |
| A21 | Lowside 12 | Main-relay coil |
| A12 | Lowside 15 | Radiator-fan relay coil |
| A2 | Highside 1 | VVT bank 1 / intake |
| B18 | Battery Sense | Ignition-switched 12 V (5 A fuse) |
| B23 | +12 V MR | Main-relay 12 V into ECU |
| A17 A18 A24 B14 B19 B20 | Power GND | Engine block → battery − |
Trigger
Do not assume 36-2. Gen 2 is a Toyota NE/G CAS in the distributor — treat like other 24+1 Toyota CAS or replace with a 36-1 crank trigger. Gen 3/4 with an aftermarket missing-tooth damper is 36-1 or 36-2 + cam. Confirm with a photo of the wheel and a composite log.
Crank
| Recommended | 36-1 or 36-2 crank trigger, VR on B5/B13 or Hall on Digital 1. |
| Factory gen 2 | Distributor NE/G. Possible but ugly. A crank trigger is a day well spent. |
Cam
| Sync | Single-tooth or half-moon Hall/VR on Digital 2 / VR 2. Required for sequential COP. |
TunerStudio
| Setting | Value |
|---|---|
| Trigger / wheel type | 36-1 / 36-2 + cam (recommended) |
| Use only rising edge | Yes on MAX992x VR (typical) |
| Invert primary | No — swap VR+ / VR− first if the gap is inverted |
| Cam as VVT input | Yes when the cam is used for sequential or VVT |
| Firing order | 1-3-4-2 |
Offset: Light on cylinder 1 (front). Transverse cars: damper mark is still TDC #1.
- ST205 factory crank/cam is usable; log it before inventing a 36-2.
Injection
High-Z on gen 3/4. Gen 2 often 430 cc. Rally cars are already on 700–1,000 cc — set req-fuel before you crank with fuel on.
| Mode | Sequential four drivers. |
| Fuel | Return, manifold-referenced regulator. The OEM pump is not a 400 kPa rally pump. |
Ignition
Gen 3 wasted-spark igniter can take 5 V logic on two channels (1-4 and 2-3). COP on gen 4: Ign 1–4.
| Dwell | 2.0–2.5 ms COP; follow the igniter if keeping wasted-spark. |
Idle
2-wire or 3-wire ISC on gen 3. PWM a low-side (A8 or A9). 12 V on the other pin.
First start
- Load the matching variant configuration in TunerStudio before the harness is live — injectors and coils stay disconnected until the decoder is confirmed.
- Fuel pump fuse out. Coils unplugged or spark outputs disabled. Crank. Open Diagnostics → composite / high-speed logger.
- Confirm crank teeth are even, the missing-tooth (or named pattern) is a single clean gap, and cam is one pulse per two crank revolutions for sequential four-stroke.
- RPM during cranking should sit in the 150–350 rpm band. 0 rpm or 12,000 rpm means the decoder is lost — polarity or wheel type, not offset.
- Lock timing to a fixed 10° (idle control off). Timing light on cylinder 1. Change trigger offset until the damper agrees with 10°.
- Recheck at ~3,000 rpm. If timing walks with RPM, it is VR polarity, a delayed Hall, or the wrong decoder — not offset.
- Enable spark. Confirm a healthy burn (timing light or plug colour) with fuel still disabled.
- Enable fuel. Prime, then crank. Catch the first idle on a rich-safe VE, then lean toward stoich at idle.
- Only then enable closed-loop idle, VVT, boost and traction. A base map is a starting point, not a dyno tune.
A base map is a starting point, not a dyno tune.