Sensors & outputs Injection
Injector — high-Z
EV14 / EV1 / USCAR · output · Injection
Saturated (high-impedance, ~12 Ω) injector. Pin A is switched 12 V from the main-relay rail. Pin B is the ECU low-side. Wire by cylinder number; firing order is software.
Typical parts: Bosch 0 280 158 040 EV14 high-Z (~930–980 cc/min at 3 bar, EV1 / Jetronic plug); Bosch EV14 USCAR; Injector Dynamics ID1050x
Note — High-Z only. Race Core low-sides are 4 A saturated drivers. That is an EV14 / LS injector, not a low-Z peak-and-hold.
Device pinout
Looking into the injector, latch at the top. Two cavities. High-Z is not polarised unless a suppression diode is fitted.
- Connector: USCAR EV6 / EV14 2-way, or Jetronic EV1 2-way
- Layout (looking into the part): A · B; polarising key top
| Device pin | Function | Type | Race Core | TunerStudio |
|---|---|---|---|---|
| A | Switched 12 V (main-relay rail) | 12 V | Fused injector 12 V rail | — |
| B | ECU low-side (cyl 1 shown) | Low-side | A3 | Lowside 1 |
Wiring notes
- Cylinder order on Race Core: 1 A3 Lowside 1, 2 A15 Lowside 2, 3 A4 Lowside 3, 4 A16 Lowside 4, 5 A5 Lowside 5, 6 A6 Lowside 6, 7 A7 Lowside 7, 8 A19 Lowside 8.
- Low-Z (peak-and-hold, 2–4 Ω) needs a resistor pack or different hardware. RB26 OEM injectors keep the firewall pack; without it a saturated driver runs hot and then fails.
- Flyback is internal. Do not add a catch diode across the coil unless a module says so.
- Fuse the injector 12 V rail 10 A for up to eight saturated injectors.
- Bosch 0 280 158 040 is the high-Z EV14 sold as about 930–980 cc/min at 3 bar. The Core EFI listing uses an EV1 / Jetronic plug. USCAR EV6 is the other two-pin family. Electrical jobs are the same: one pin switched 12 V, the other the low-side. Confirm which housing is in your hand before you order the plug.
Failure modes
- One cylinder dead, the others fine: that low-side or that injector plug. Firing order in software does not renumber the pins.
- All injectors hot, or the driver faults immediately: low-Z injectors without a resistor pack on a saturated low-side.
- Fuel pressure collapses as soon as they open: the injector 12 V rail is fused too small, or it was taken from the ECU instead of the main-relay output.
See also
- Relay — injector 12 V comes from the main-relay output, not from an ECU pin.