What kind of power does the EFI relay provide?
The EFI relay provides switched 12V power then to the injectors, ignition coils and also back to pin 7 on the ECU, which is the main power input. The output must also be configured as “EFI relay” Thank you and happy learning.
Can a modular ECU drive an EFI relay?
Modular ECUs have the ability to drive an EFI relay, and if your application doesn’t require ECU control of an EFI relay, you can use this output as a fuel pump relay control. This output can only switch to ground, it can’t source current (that is, drive an output high). So if it’s going to be used to drive a relay
Where is the fuel pump relay output on an ECU?
The EFI / fuel pump relay output triggers the negative of the fuel pump relay. The setting in the ECU must be set to be fuel pump relay, and you can find it under Functions -> EFI / Fuel pump relay output. If you want to disable the fuel pump relay, then you can set it to “none”.
What happens when the relays are turned off?
The diodes in anti-parallel will help suppress the spikes when the relays are turned off (The stored energy in the magnetic field is converted back into voltage/current causing a spike that may be inductively and capacitively coupled back in to the mains).
Where is the EFI relay on an ECU?
If you want to use the output to control an EFI relay instead, then connect the ignition switch into pin 17. Pin 16 becomes the EFI relay coil negative. The EFI relay provides switched 12V power then to the injectors, ignition coils and also back to pin 7 on the ECU, which is the main power input.
Can a fuel pump be used as an EFI relay?
In this case, the output function should be configured as “inverted fuel pump”, and use an external pull-up resistor on that output to 12V or 5V to generate the high voltage. If you want to use the output to control an EFI relay instead, then connect the ignition switch into pin 17. Pin 16 becomes the EFI relay coil negative.
Do you need ground and voltage for EFI?
When installing a Holley or any EFI system to your vehicle, it’s imperative to have a proper ground and voltage for the system. The internals of an ECU contain delicate microprocessors and many other components that rely on clean, sound power and ground.
Where is the best place to connect the EFI to the battery?
1) Always Connect Directly To The Battery: The best place to connect the main power and ground for the ECU is the vehicle’s battery. By connecting the EFI’s main power and ground this way, allows the battery to act as a capacitor which filters the power going into the ECU.