I picked up an '87 IROC. Im going to be putting a carb'ed motor back in..all non CC. I know some part of the computer has to stay. So my question is, what all wiring do i need to leave under the hood before i cut the rest off? And how do i distinguish them?

 

Don't cut anything. It can all be removed in one piece. It's the stuff that goes to the passenger side fender well. What you need is on the other side of the firewall.

 

So everything that is in the engine bay on the passenger side fender well can be removed? The computer isnt mounted under the dash anymore either..its laying in my passenger floorboard. So should i just mount that back up?? I thought i would need something because i thought there were some wires that had to run to the distributor...sorry im a little new at this..

 

The ignition power goes to the coil, and comes from the driver's side rear corner of the engine compartment.

So, yes, everything that's part of the harness that goes to the passenger side fenderwell can be removed in one piece. Remove the plastic fender liner, you'll see the connector that passes through to the passenger compartment - disconnect it there.

If you have auto transmission (TH700R-4), you'll need to rig up a way to lock up the torque converter clutch. That's a computer function, and may be one reason to cut the ECM harness. Just so you understand, even if you leave the computer in there, it still won't do that function without the other computer inputs. Since this is an '87, it also has an in-tank electric fuel pump that is run by the computer.

For the record, the factory computer controlled q-jet is the best possible street performance carb you can get. I'd suggest you seriously consider keeping it if it hasn't been FUBAR'd.

 

When I removed the computer, I had to reground the VSS to make the cruise control function--if that's important to you. Also, on the T5, the reverse lights (as seen in the following pic) run through the harness.

https://www.thirdgen.org/forums/engi...-function.html

JamesC

 

I am doing the same swap...a carb'd engine into a 87.
so,all of the hookups to the senders aren't on this harness but the other one?
I havnt touched the car yet,still gathering info.
and on my 87 car,the engine in it has a manual pump instead of the electric one in the tank.The previous owner done this before I got it,which was what I wanted to do to it anyway.
and what tips ,if you remove the harness, is out there to lock up the torque converter clutch?

 

'87 carb'd cars had both the engine-mounted mechanical and in-tank electric fuel pumps from the factory.

If you remove the ECM harness, you have to rig up the TCC lockup. Search the Transmission and Drivetrain forum.

 

on the car i have,none of the wires are present at the fuel pump relay.I am assuming the in tank pump is gone.
and thanks for the tcc help

 

im plannin on goin to a fuel cell anyways. this car is gonna be more of a track car that ill occassionally take out on a nice Saturday or somethin. so i can actually take out the computer and all of the wiring thats on the passenger side and all ill need to do is rig up something for the TCC lockup?