Applications Honda H22
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.
Honda H22A
2.2 L Prelude DOHC VTEC. Distributor ignition on the common H22A and H22A4, high-impedance injectors, cable throttle, VTEC solenoid. 2157 cc. Firing order 1-3-4-2. Not a K-series: do not select the 12-1 crank mode from the K20 note. Not an F20C: that engine has its own note.
Recommended: F7, V4 or Micro Core. Four injectors, VTEC on a high-side, ignition through an igniter until you convert to logic COP. 36-1 is the named-decoder path.
Status: draft. Trigger offset has not been confirmed on a running Race Core install.
- Cylinders: 4
- Displacement: 2157 cc
- Firing order: 1-3-4-2
- Orientation: Cylinder 1 at the timing-belt end. On a Prelude the belt is on the right of the bay. Firing order 1-3-4-2.
Variants
| Variant | Years | Trigger | Notes |
|---|---|---|---|
| H22A / H22A1 | 1992–1996 class | Distributor | VTEC, cable, high-Z. OBD1. |
| H22A4 | 1997–2001 | Distributor, some cars also have a crank sensor | OBD2. If a crank sensor is present, log it. Do not assume it is a K20 12-1. |
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 |
| A1 | Highside 2 | VTEC solenoid, on/off |
| 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
No H22 row in the rusEFI list this note used. K20 12-1 and F20C modes stay on those engines.
Crank
| Usual path | 36-1 Hall or VR. |
| Factory distributor | Unsupported until logged. |
| H22A4 crank sensor | Pattern TBD. Log before you name it. |
Cam
| Sequential | Digital 2. VTEC oil pressure is not a cam pulse. |
TunerStudio
| Setting | Value |
|---|---|
| Trigger / wheel type | 36-1 + cam, unless a log names something else |
| 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.
Injection
High-Z sequential four. Prelude injectors are port. Meter them. 2157 cc required fuel is not a D16 number.
| Impedance | High-Z. |
Ignition
Distributor internal coil: igniter on Ign 1, module pins TBD. COP conversion: Ign 1–4, dwell 2.0–2.5 ms.
| VTEC | Does not change dwell. It changes the cam. Tune VTEC as a switch, not as a trigger. |
Idle
2-wire IAC, pin TBD. Cable throttle. VTEC solenoid Highside 2. The F20C and K20 VTC phasers are not this engine — H22 VTEC is the on/off solenoid plus a mechanical rocker, not a PWM cam phaser.
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.