Custom Fuel Injection Harness
This guide provides an overview of the custom fuel injector sub-harness, lists common connectors used, and outlines steps to build a new harness that replicates the OEM design, excluding the MAP sensor.
Custom Fuel Injector Sub-Harness Description
The Honda RC51 custom fuel injector sub-harness connects the following sensors to the ECU:
| Sensor Name | Description | Connector Type |
|---|---|---|
| Throttle Position Sensor (TPS) | Monitors the throttle valve position. | Sumitomo 6189-0154 |
| Injector 1-1 | Fuel injector for cylinder bank 1 (front), primary | Sumitomo 6195-0043 |
| Injector 1-2 | Fuel injector for cylinder bank 1 (front), secondary | Sumitomo 6195-0043 |
| Injector 2-1 | Fuel injector for cylinder bank 2 (rear), primary | Sumitomo 6195-0043 |
| Injector 2-2 | Fuel injector for cylinder bank 2 (rear), secondary | Sumitomo 6195-0043 |
The injector connectors have a high key—ensure you use the correct type. You can find a link to the correct connector here. These specific connectors do not have anti-rotation tabs, which are not critical for this application.
This custom harness uses opposite injector numbering compared to Honda’s original convention. I saw no reason to label the rear cylinder as number 1 when the firing order is front-rear. This was a personal preference. Be aware that this may cause confusion when referencing the OEM service manual due to the reversed numbering.
Assembly of this sub-harness is straightforward: replicate the OEM design and omit the MAP sensor connector if you're using a built-in MAP sensor, as with the FT550.
Sourcing the Connectors
There are several reliable sources for the connectors used in this sub-harness. Below are websites I’ve personally used and found to offer competitive pricing:
Mouser and Corsa Technic are especially helpful because they list actual manufacturer part numbers for connectors, unlike ProWireUSA. TE Connectivity is a great resource for connector datasheets, particularly for the DT and DTM series.
Custom Fuel Injector Sub-Harness Images
Explore this collection of images showcasing the custom fuel injector sub-harness and its installation.
