Dec 7, 20071993 MKIV Toyota Supra E85 Project- Sep 2007
The C1 connector(yellow connector near igniter) has 2 wires that you will use if you use the EFI main relay in conjuntion with the circuit opening relay.
Wires that you may need from this connector:
Black/Orange - (M-REL on ECU, not required) - Used as the activating power to the EFI Main Relay
Black/Yellow - (BATT on ECU, required) - constant power, use a 7.5 amp FUSE
EFI Main Relay - In the Supra turbo and other Toyota Turbo vehicles, the ECU conrols the EFI Main(M-REL off the ECU),. In Toyota non-turbo cars and trucks, the EFI Main is controled by the ignition switch. You don't have to change this, as I have not seen any problems running it this way, unless you are picky and want to have it exactly the same as the turbo configuration.
If you do want to run it like the 7MGTE, you will have to cut the relay coil power wire that goes into the EFI main. The location of the EFI main will vary depending on the year of your vehicle. You will need connect the M-REL wire from the C1 connector, and use it to power your factory EFI main. Again, this will be the Black/Orange wire at the C1 connector. The output of the EFI main should then supply the power to the Circuit Opening Relay.
The Circuit Opening Relay(COR) is what supplies power to the fuel pump. The power that is sent to the COR then to the fuel pump comes from the EFI Main Relay, so the EFI main must be activated before power can be supplied to the COR. The COR has a dual coil for activation, one of the relay coils can be activated by the starter. This is done by supplying power from the starter wire to the relay coil which has a constant ground. That wire is a small guage black wire with blue stripe coming from the large yellow connector (B1) by the ECU. Just tie this wire into your starter wire. The other coil is activated by the Fuel Control, or FC (B1 connector) from the ECU. The ECU sends a ground signal to the COR, and if relay has power from the EFI main relay(discussed earlier), then the COR will supply power to the fuel pump, or the Fuel Pump Control Relay if you wish to use it. If you are running a non-turbo engine, the COR is controled by the green wire going into the AFM, not the ECU. You can splice into that green wire and tie that into the green wire on your project vehicles AFM connector. That will take care of the pump problem.
Fuel Pump Control Relay(FPCR) - (Not Required)- Once power is able to pass through the COR, there is then a FPCR. This is just a resister to change the voltage to the fuel pump. I have run many swap without this without any problems or any changes in gas mileage. This recieves power from the COR for both the contact switch, and the relay coil. The ground is controled by the FP (B1 connector) signal coming from the ECU.
Both the FPCR and COR are not needed to make this run properly, but you will need to find an alternate way to control the fuel pump. At first I just had mine connected to the ignition switch. Problem with that, is your fuel pump is always if your ignition is on(like if you get in a wreck, you pump will keep pumping fuel....not good).
In short, if all that was confusing, the only thing you really need to do on the C1 connector is hook the black/yellow wire to constant power. Then for the fuel pump control, hook the green wire up the the FC from the ECU. The 7MGE(non-turbo), does not have a FC from the ECU, instead you will splice the green wire into the 7M engine harness near the 7M AFM connector.
I hope after all this, you aren't confused too much.
E-mail me at firstname.lastname@example.org for questions about this that you don't understand, so I can try to exlain it better.