EJK Controller Installation

The goal of the installation is to gain access to the injector signal in order to change the signal which fires the injector and fuels the vehicle.

First step of the installation is to remove the necessary bolts and parts to gain access to the injectors. First make the connection to the injectors.

Once the injectors are located then the installation is the same on all vehicles. First remove the factory injector connector. Make sure not to just pull on the connection. Most connectors have a release clip which locks the connector in place and needs to be pressed in order to release the connection.

Most EJK controller installations plug in right at the injector. These typical installations will have a male and female connector grouped together on the EJK harness (refer to Figure below). For 2 or more cylinder vehicles there will be the equivalent number of connector groups on the EJK harness. Some applications install at a sub-harness location to make the installation easier. These EJK applications will have a larger connector with usually 4 or more wires being plugged in.

The owners manual will be a big help, it often explains where and how to access injectors.

Second step is to plug the similar EJK harness connector back onto the injector. Final step is to plug the other EJK harness connector into the stock injector connector which you originally took off (refer to Figure 2 for a completed install on 1 injector). For multiple cylinder vehicles you may have to repeat this step for all the injectors. TO AVOID CONFUSION PLEASE ONLY DISCONNECT ONE CONNECTOR AT A TIME.

The final and most important step - GROUNDING.
One of the largest causes of controller erratic behavior is associated to improper grounding. All EJK controllers have a black wire with a ring terminal which during installation needs to be secured to a proper grounding location.

If your vehicle has a battery then attach the EJK controller black wire to the negative terminal of the battery. The ring terminal can easily be cut to allow fitment around a larger terminal post or bolt.

For vehicles without a battery then an alternative grounding location must be determined. The grounding location must be metal. Any location with a bolt into the metal frame is a good location. Be sure to make the connection secure so vibration can not cause the wire to become disconnected.

FINAL STEP: Mounting the EJK controller. There is no exact location where the EJK controller has to be mounted.

The EJK controller is very small in size to allow for mounting in small places. Typical mounting locations are under the seat or in the air box. A Velcro patch is supplied with the EJK controller to hold the controller in place while riding, but allow for the controller to be pulled out to make adjustments if necessary. Be sure to determine a location which does make the controller accessible without having to take off too many other parts.

Zip ties are also included in the packaging to help secure the harness around the frame and away from high heat sources and moving parts. Be sure to route the harness in a way where the vehicle can be freely operated without pulling on the controller connections.

A number of newer vehicles implement the use of narrowband O2 sensors to help target a desired air/fuel ratio (AFR) for the engine to operate at. For racing and performance scenerios the O2 sensors must be bypassed in order to allow for complete range of tuning. The purpose of bypassing the O2 sensors is to allow the vehicle to run in open loop mode where fuel adjustments can be made freely. When the vehicle is using the O2 sensors to make fuel trim calculations it is said to be in closed loop mode. Attempting to make fuel adjustments while the vehicle is in closed loop mode can create erractic drivability as the stock system continually tries to trim back to the desired AFR.

How to interface with the O2 sensors is different from vehicle model to vehicle model. The goal of properly bypassing the O2 sensors is to not throw an engine code and allow the fuel to be freely adjusted. Some vehicles require the O2 sensor connections to simply be disconnected. Some vehicles require an O2 bypass module to be plugged into the stock O2 connections. And still other vehicles have additional connectors on the EJK harness to plug into the O2 sensors similar to installing onto the injectors. If your vehicle is equipped with O2 sensors then be sure to find out how you are suppose to interface with them. This information can be found by browsing to the particular product for your vehicle.