Applications Toyota 4A-GE
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 4A-GE
AE86, AE92, AW11 and Corolla 4A-GE. 1.6 L twin-cam. 16-valve engines are distributor and cable throttle. 20-valve Silvertop keeps a distributor and individual throttles. 20-valve Blacktop is coil-on-plug. All of them are high-impedance port injection.
Recommended: F7, V4 or Micro Core for a cable-throttle four-cylinder. Only the F7 pin table below is published. Blacktop COP uses four logic coils. 16-valve and Silvertop need an igniter, or a COP conversion, because a logic output will not drive a dumb coil negative.
Status: draft. Trigger offset has not been confirmed on a running Race Core install.
- Cylinders: 4
- Displacement: 1587 cc
- Firing order: 1-3-4-2
- Orientation: Cylinder 1 at the timing-belt end. Firing order 1-3-4-2.
Variants
| Variant | Years | Trigger | Notes |
|---|---|---|---|
| 4A-GE 16V | 1983–1991 | Distributor | Bigport / smallport, TVIS on early bigport, cable throttle, AFM. AE86, AE92, AW11. |
| 4A-GE 20V Silvertop | 1991–1995 | Distributor | AE101 individual throttles, 11:1, distributor ignition. |
| 4A-GE 20V Blacktop | 1995–2000 | COP, pattern not a named rusEFI mode | AE111 individual throttles and four coils. Log the trigger or fit a 36-1. Do not invent the tooth count. |
Recommended pin assignment (Race Core F7)
Pins below are the library default Race Core F7 map — the same AMPSEAL landings as the verified 1UZ-FE, 2JZ-GTE and LS1 notes. Core EFI V4 and Micro Core cavity numbers are TBD. If a pin is not in this table, it is TBD. Do not guess a spare.
| Pin | TunerStudio | Function |
|---|---|---|
| B5 / B13 | VR 1+ / VR 1− | Crank, if the sensor is 2-wire VR |
| B10 | Digital 1 | Crank, if the sensor is 3-wire Hall |
| B4 / B12 | VR 2+ / VR 2− | Cam VR |
| 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 |
| A20 | Lowside 10 | Fuel-pump relay coil |
| A21 | Lowside 12 | Main-relay coil |
| A12 | Lowside 15 | Radiator-fan relay coil |
| B17 / B16 | CAN 1 H / L | Dash / wideband |
| 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 − |
| C9 / C21 / C32 | 5 V Sens 1 | MAP, TPS, pedal 1 |
| C1–C8, C29, C31 | Sensor GND | 0–5 V and thermistor returns |
Trigger
There is no 4A-GE row in the public rusEFI trigger list used for this note (the Toyota modes there are 12-tooth crank, 36-2, Toyota 3-tooth, and Toyota 4-1). A distributor pickup is not one of those modes.
Crank
| 16V / Silvertop | Distributor. Do not pick a 2JZ 12-tooth or 36-2 decoder for it. |
| Recommended conversion | 36-1 Hall on Digital 1 (B10) or VR on B5/B13, plus a cam on Digital 2. |
| Blacktop | Coil-on-plug. Tooth count is TBD until a composite log exists. Fit a 36-1 if you are not logging the factory wheel. |
Cam
| Distributor engines | The distributor is the phase reference. Sequential fuel still wants a cam pulse you can name. |
| 36-1 conversion | One cam pulse per two crank revolutions on Digital 2. |
TunerStudio
| Setting | Value |
|---|---|
| Trigger / wheel type | 36-1 + cam after the conversion. Factory distributor: log it, do not guess a mode |
| Use only rising edge | VR: typically yes on MAX992x. Hall: as logged |
| Invert primary | No — swap VR wires first |
| Firing order | 1-3-4-2 |
Offset: Light on cylinder 1 at the timing-belt end. Do not copy a 2JZ 65° offset.
Injection
High-impedance port injectors. Meter them. Early 16-valve looms are often batched; cut the pairs for sequential. 20-valve engines are still port injection, one injector per throttle on the ITB cars.
| Impedance | High-Z. Race Core low-sides are saturated only. |
| ITB | Alpha-N, or MAP in a balance manifold. A single runner vacuum signal is a bad MAP. |
Ignition
16-valve and Silvertop: one ignition path into an igniter (Ign 1). Blacktop and any COP conversion: Ign 1–4 in cylinder-number order, firing order in software.
| Dumb coil | Logic outputs do not drive a coil negative. |
| COP dwell | 2.0–2.5 ms for a logic coil. If a coil is hot after 30 s idle, dwell is too long or 12 V/ground is poor. |
Idle
Cable throttle. 16-valve idle is a 2-wire or 3-wire air valve depending on year — identify it before you assign a driver. The spare low-side pin for that valve is TBD (pump, main relay and fan already own Lowside 10, 12 and 15). ITB cars often idle on a small air bypass, not a GM stepper. Do not spend the H-bridges on a stepper you do not have.
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.