87t ecu harness into 86t ?

You unplug the 86T ECU and plug in the 87T.

They use the same O2.

http://www.redz31.net/pages/fuel.html

I looked up the wiring schematics for 87t and 85na, all 3 wires seem to go to the same places. Only concern was pin 115 on the ecu. Both schematics show a yellow wire runs from o2 to pin 115. Some people report pin 115 being empty. I haven't confirmed this in my car yet, but I'd guess if its empty then run that wire to pin 115

I don't have the 86t harness anymore, so im gonna have to use the 87t harness. the 87 harness has a green wire, a black wire, and another wire (im guessing yellow) same color as wire that goes to eng temp sensor on the lower plenum. but the "yellow" wire goes nowhere on the harness. the green wire and the black wire (wrapped in grey sheath) which is actually 2 wires run down to the plugs, but this last wire.....should it go to the ecu? the car ran with the harness like this a few months back.

The wiring diagram shows that wire goes to pin 115, I've read of people grounding that wire but that made the o2 not function. I'd suggest running it to 115

awesome. thanks.

Yw, let us know how it goes, this will confirm my research. Lol.

will do, I have the harness all opened up, I want to go thru and get rid of any un necessary wires. just thought it was weird that yellow wire didn't go anywhere and there were no broken wires it could have met up with

the orange wire that runs between pin 30 and the, my 87 t harness has that orange wire never going to the afm plug. why?

i have 2 other harnesses, i been comparing them and the other 2 i have, have 6 wires that go to the afm pig tail. on the 87t harness, the afm pig tail has 5 wires. can someone verify if i need that orange wire?

bump. still curious.

Like I said, there shouldn't be any difference in the harnesses. I ran my 86NA with a factory engine harness from and 85T on an 87T ECU and everything worked fine.

The only difference is 87-89s use a single wire fusible link versus the 84-86 using 2 fusible links. Thus, the power source wiring needs to be modified slightly.

Did you use the o2 sensor from an 85t or 87t?

No O2, I'm running a wideband.