Applications Nissan CA18DET
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.
Nissan CA18DET
The SR20’s older cousin. Optical CAS 360+4, wasted-spark or dizzy, low-ish cc injectors. Same 360 CAS rule: do not decode the outer ring.
Recommended: F7 or V4. Four sequential, COP conversion, 36-1 crank trigger.
- Cylinders: 4
- Displacement: 1809 cc
- Firing order: 1-3-4-2
- Orientation: Cylinder 1 front. S13 180SX/Silvia, U12 Bluebird.
Variants
| Variant | Years | Trigger | Notes |
|---|---|---|---|
| CA18DET S13 | 1989–1990 | Optical CAS 360+4 | T25 turbo, ~370 cc, wasted spark on later, dizzy on early. |
Recommended pin assignment (Race Core F7)
| Pin | TunerStudio | Function |
|---|---|---|
| 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 |
| 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
Identical CAS problem to SR20. Fit 36-1 + cam Hall.
Crank
| Recommended | 36-1 Hall/VR. |
Cam
| Sync | Digital 2, one pulse per cam rev. |
TunerStudio
| Setting | Value |
|---|---|
| Trigger / wheel type | 36-1 + cam |
| Use only rising edge | Hall: as logged. VR: typically yes on MAX992x |
| Invert primary | No — swap VR wires first |
| Firing order | 1-3-4-2 |
Offset: Light on cylinder 1.
- 360 CAS not supported.
Injection
High-Z ~370 cc OEM. Sequential four.
| Fuel | Return, 1:1 regulator. |
Ignition
COP on Ign 1–4 preferred. Factory igniter is 5 V logic on two channels if wasted-spark.
| Dwell | 2.2–2.8 ms COP. |
Idle
AAC 2-wire, PWM low-side.
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.