Cars · Wiring
Peak and Hold (Low Impedance) Injectors
Technical overview of Peak and Hold (low impedance) fuel injectors, their operation, and the requirement for resistor boxes in Honda systems.
Peak and Hold injectors (commonly known as Low Impedance injectors) are a type of fuel injector used in high-performance applications.
Technical Overview
- Impedance: Typically 2â5 $\Omega$ (Ohms).
- Current Draw: Draws significantly more current than high-impedance injectors (~6â2.4 Amps).
- Operation:
- Peak: High initial current is applied to open the injector solenoid quickly and crisply.
- Hold: A reduced current is maintained to keep the injector open.
Compatibility
The high current draw of these injectors can damage ECUs that are not designed to handle the load.
- Resistor Boxes: To run low-impedance injectors on ECUs expecting high-impedance injectors, you must utilize an inline Resistor Box to limit the current draw to safe levels.
- OBD0: Factory-equipped with a resistor box.
- OBD1/OBD2: Factory-equipped for high-impedance injectors and do not have a resistor box. If swapping to low-impedance injectors on these systems, an external resistor box must be added.
Always verify your injector impedance and ECU compatibility before installation to prevent driver circuit failure in the ECU.