AE86 Standalone Management

[Olie]

Hey Guys,

I've got a 1984 AE86 Trueno (JDM), it's running a 16v 4AGE with 20v ITB's and a Cusco ECU with Apexi AFR controller. Since it wasn't quite running right, I've decided to remove the previous ECU and run a standalone engine management system (Emerald K6!).

At the moment I'm almost done building the loom but am a little stuck wiring in the relay controls, does anyone know how best to wire up the:

*Main Relay Control
*Fuel Pump Relay Driver

*Ignition Sense Input




Its difficult to trace back as the relays don't correspond exactly to the pins under the relay box. From the wiring diagram above I'm assuming I can take the ignition sense input from the wire marked B-O (Left of the EFI main relay), and then use the Emerald 'Fuel Pump Relay Driver' to control the EFI main relay, which controls the circuit opening relay and therefore the fuel pump. But then where does the Emerald Main Relay Control come into?




I was also wondering where its best to obtain a +12v supply for the Emerald ECU, I'm told it can either be from the Main Relay, or common with the ignition sense input..

Any help will be greatly appreciated

Oh and here's the car:

[jondee86]

Since I don't know how much of the original wiring you have, I can only
comment in general terms. This is how it happens with the factory ECU...

Turning the keyswitch ON will supply power directly to the injectors, ignition coil
and igniter. It will also put 12V on the EFI Main Relay coil. When the EFI Main Relay
contacts close, power is supplied to the ECU and to the RUN coil of the Circuit Opening
Relay. Once the AFM grounds the COR coil, the fuel pump will be energised.

And this is how I see it happening with your new ECU...

1. EFI Main Relay. This can be powered from the keyswitch as per the OEM
arrangement, and you use the relay output to power up the Emerald ECU. This output
will also supply power to the RUN coil of the COR.

2. Circuit Open Relay (Fuel Pump Relay). Assuming that you will be using a MAP
sensor instead of the AFM, the Fuel Pump function of the the Emerald ECU will be
used to ground the COR RUN coil. As you no longer have a cold start injector, you will
program the Emerald to prime the fuel pump for a couple of seconds, and to provide
cold start enrichment.

3. Ignition Sense Input. I'm not sure of the function of this input ? It kind of implies
that the Emerald has a permanently ON power supply, which would be different to the
arrangement I have outlined above. Never the less, if the ECU needs to know when
the keyswitch is turned on, the easiest place to tap would be the coil/igniter power
supply.

Cheers... jondee86

[burdickjp]

You don't need to touch the OEM chassis harness. Everything can be done in the Engine harness.

The G-R wire originally going to the AFM is used to ground the circuit open relay to drive the fuel pump. You can run this to the ECU as the fuel pump.

The B-R wire coming from the EFI relay is used to power the fuel pump and ECU. No reason to do otherwise. Use it to power your ECU, and FUSE YOUR ECU. This runs through the engine harness from by the battery, all the way to under the dash. That plug under the dash is power to the fuel pump. So you'll have a splice somewhere between there for your ECU.

I used B-O to power my injectors and coils.