Im not sure if this helps but here is a how to i did for fitting the safc to a nissan s12. It should be reasonably similiar to set up on the gtir.
Now the way the SAFC does it's job is by being connected to the computer. Here is a picture labeling where each wire needs to be connected to in order for the SAFC-2 to work.
Gray is tapped into the TPS.... stock S12's do not have TPS's (they have ONE switch) so this can was left untapped. Im not familiar with gtir sensors but u will get the idea.
The yellow is the SAFC's MAF output. This wire will eventually be connected (inline not spliced) to the ECU's MAF input. It will give the computer the "corrected" MAF signal
Ground 1 is connected to the ECU's ground wire and should be spliced into the wire farther away from the ECU after.......
Ground 2 is connected to the same wire a little bit closer to the ECU compared to the splice for ground 1
The green wire is the RPM signal. Obviously you will splice into this wire from the ECU's RPM signal input.
The white wire is the SAFC's MAF sensor input. This wire will connected to the MAF sensor output.
when you cut the ECU's MAF input you will connect the MAF portion to this wire and the ECU part to the yellow wire get it?
The Blue and purple wires are the MAP (manifold aboslute pressure sensor) sensor input and outputs for the SAFC. . If It doesn't use a MAP sensor for metering fuel. So obviously don't do anything with them.
I don't have the instructions anymore and I forget what the orange one is for but I made this picture when I had them so I'd say the orange isn't used either.
The purple wire will be spliced into the Knock sensor input wire.
and finally the red wire is the 12v power source which you will also get from the ECU's power wire.
One it's all wired in you're good to....
Setup the SAFC.
First you will have to tell the SAFC how many cylinders the car has, what type of metering system the car what metering sensor the car has and what type of TPS the car has.
So here's how you do it.
Turn the key to the on position DO NOT START THE CAR IT I WON'T RUN ANYWAY.
Then the SAFC should start dancing around
use the stick to scroll to the etc. menu and press the button
Then go to car select
This screen is what you will see
So using the pad set the # of cylinders to 4 then go over and set the "thr"(tps)
Go back to the etc. menu by pressing left on the stick. Then go to sensor type
You will see this screen
continue by pressing into the Hot-wire selection
You will see this screen
Except for the fact that 01's will be the default and you will see them in place of the 04's. 04 is for the the CA18DET (s13)sensor which i had on my s12. Now if you put different numbers in the SAFC will convert the sensor's voltage range you currently have (say a 300zx TT sensor) into what the computer is progammed for allowing you to use a different MAF sensor (so long as it's measuring capacity is more than the stock one othewise the car won't run right anyway) without having to hack into the computer's ROM and rewrite it.Once you've done this the car is ready to drive. However you should set the knock sensor correction while you're here.
Start the vehicle now go back to main menu and go to the setting's menu. In there scroll to knock set
now while the car is running of course raise the engine to around 1500 RPM then press right on the stick. This tells the SAFC that this raw knock sensor output is "normal"
Then raise the engine RPM to 3000 RPM and do the same thing.
The result should be around this but the numeric values might be different
Setup is complete, install larger injectors, tune with a wide band
Problem two is the Apexi site does not seem to have the information i need.
