bkm_rx7

ok, ive read thru all of "13b in a FB" threads and think that i have a REAL good grasp on everything about this swap except for the electrical piece.

ive never dealt with EFI before, but it sounds very simple. im planning on modifying/chopping an FC wiring harness to work in my gsl-se. what i need to know is what stuff can stay in tact on the harness and what stuff needs to be chopped or replaced.

i also wanna take pics along the way to help other people thru this difficult part of the swap...but i need the experts' help to guide me to begin with...THANKS!

680RWHP12A

chop an fc harness.. well your off to a bad start!!!

you need a complete turbo 2 engine harness and a turbo 2 ecu to start with.. then you need to make a different wiring harness from the pickup module to the ecu.....

now, thats a good start!!!

Kingbob

yeah, basicly you take the stock TII harness and stock TII computer, and then tattoo the 1st gen wiring diagram onto the back of your left eyelid and the 2nd gen diagram on your right. because you will need to study them that much to really understand what's going on. It's pretty easy once you get used to looking at it and get a grasp of what the computer needs and what it doesn't. (which is application dependent). It took me less than a week to swap a n/a 13b into an '84 GSL.

oh, be sure to get the WHOLE shielded cable for the cas from the donor car and it will make your life much easier.

Rex4Life

Here ya go--schematics and pinouts for an 88 T2 into an 84 GSL-SE:

http://home.houston.rr.com/mazdarx7/ecu_map.htm

Make sure you read over the WHOLE web site before you start asking more questions. Note there are "tabs" at the bottom of the page that navigate to other pages.

Scott

bkm_rx7

hey...thanks...even tho ive already got all that stuff on my comp just in case my internet goes down...i need to make it bigger and print it out...ive done like 10 hrs worth of reading about this swap...

oh...good thing about that fc harness...turns out i cant use that one anyways...its not mine

oh well..i have a t2 harness on the way...

bkm_rx7

oh...and just wondering...since i will be using a t2 harness and t2 ecu...whats keeping me from just using both wholly?

gsl-se addict

iTrader: (3)

Most of the stuff you can use directly (engine -> ECU connections). The mods that you need involve the other stuff (power to the ECU and injector, tach signal, 20k switch, etc.). If you follow what Rex4Life posted, it should be pretty straight forward.

steve84GS TII

Its not all that hard.Ive done both S4 and S5 in my 84.
The way to approach it is not to think about chopping or splicing anything.The big right side harness you leave alone completely.It connects the ECU and the majority of the engine together,theres no need to cut or modify anything.

For the smaller left side harness,just gather all the compenents you need to power,and MAKE a completely seperate harness from scratch.This includes......

L coil
T coils
FC main relay
Fuel pump relay/resistor
Fuel pump
CAS (S4 only)
Circuit opening relay

All these things can be connected to the ECU completely independant of the rest of the car's wiring.Use an FC main fuse box too,its way better than the FB's fusible link setup.The left harness will need about 15 wires total.There are many other pins in that ECU plug that you wont need,like AC and PS sensors,voltage load sensor,shift light,blower relay,ect.All extraneous stuff you can leave out.The left harness will basically handle all the power on/off stuff for the ECU and fuel pump.The right side harness is more about sensors and input/output devices.
Use the FSM and an old wire harness from a junkcar to make the new harness.Lay everything out carfully to get the lengths right and solder/shrink tube all the joints.Its not that hard and itll look factory original when your done.

bkm_rx7

ahhhhh...gotcha...so ill just be adding to the harness mainly...not chopping so much...GOOD!

steve84GS TII

If you run the FC fuse box,there will be no chopping of the FB at all.This is especially nice in case you ever want to switch back to the FB engine.Just run the new left side harness through the firewall,down under the carpet by the pedals,and over to the ECU on the passenger's side.I mounted the FC coils,fuel pump relay,fuse box and main relay all on the drivers side fender to keep it clean/simple.Its easy and stock looking because everything is grouped together like it is on the FC chassis.

bkm_rx7

oh excellent...thx for the info...im planning on putting the fusebox in...do you have any pics of how you mounted all the stuff in your engine?

steve84GS TII

If you look really close you can see everything here.
Starting from the firewall and working forward on the drivers side,you have the FC main relay,the trailing coils,leading coil on the strut tower,FC fusebox and fuelpump relay/resistor.