I started my 1986 Carb to 1986 TPI swap this morning. I began by removing all the computer controlled connections from the ECM side harness. Fairly simple and straight forward. It took about 1 hour. I removed the computer and pulled the harness through the fire wall. Now this is what seems silly to me. I have been told by everyone under the sun that I did not need the drivers side wiring harness because they are the same. After removing the ECM wiring harness I still have the fan relays and wiring, it is connected to the drivers side harness. My new 1986 TPI harness has that connected off the ECM wiring harness. WTF. The old lines that went to the electic choke and stuff are all still there because they are on the drivers side wiring harness. Do I just cut and tuck them? I am going hummmmm right now as I stare at her. I am going to go ahead and install the intake manifold and call it quits til I get some expert advice. Thanks guys

Tony

 

i'm about to do this swap on my 86, i played around with the harness before, i'm going with a 91 harness that's totally different has the fan harness integrated with it cause the fans are controlled by the computer.

all that wiring on the driver harness has nothing to do with the computer, thats the electric choke, gauges and the stock single electric fan, the tpi stuff doesnt use that, you can tuck the wires away or cut them, if you could get the whole driverside harness that screws in to the bulkhead, i think there are 2 sides.

on mine i'm just going to do away with the wires cause i never want to look at that carb again, the fuse blocks are different there is no crk, inj1, inj2 fuses.

when you disconnected the ecm harness there was a clear connector you unplugged also these are different on the tpi cars this is where the injectors and other sensors, "integrate" with the car to get power from the fuse block.

like i said i've done a lot of research but i didnt start my wiring yet, any more questions just ask, do searches here, theres a lot of info

 

Great info! I can understand cutting and tucking all the old wires from choke and stuff like that and the old fan relay and wiring. I am a bit concerned at the distributor. It has 2 connections coming off of it, 1 goes to the dist cap and the other should connect to the ECM wiring harness. My dist has a long oval type connector that accepts the matching 4 port plug. My wiring 1986 wiring harness does not have this matching plug on it. There are 3 cut wires on the harness near where the dist plug should be on the ECM wiring harness. The guy I got it from said they were ground ring connectors to the rear of the block. I am kind of confused. I will upload some pics later tonight to help explain my situation a little better. Are you needing any parts for your upgrade. I have collected a few extra odds and ends over the last 6 months.
Tony

 

The drivers side harness is pretty much gauges, lights,fans. You will probably need a non-computer controlled distributor but I may be wrong on that. As far as the fans. Just hot wire them to a switch or by a kit that allows you to control them. I also am about to do the same swap after a while. I yanked the wires on my 85 carb'd z28 and all the wires on the ecm side were junk. You will loose the back-up lights if im correct, or well I did.

 

pay no attention to that, he has it backwards, i'm thinking he thinks your swapping to a carb from tpi

you will not loose your backup lights, the backup lights travel from connector c207 out the ecm harness to the transmission

GM used 2 distributors, 1 was a big coil in cap, the other was a remote mount and smaller, i dont believe they used the small one in 86, worst case is you would have to get a different distributor. what color wires are the ones that have been cut? do you have a service manual?

 

How am I backwards?? I know he's doing a TPI to carb'd swap.
And if the backup light wiring is on the ECM harness and he's taken out the ecm harness, hows he gonna have back-up lights?? The drivers side wires on the camaros are prettty much the same.They go to the fuse box inside.

 

I just got the service manual from my buddy a couple hours ago, *** its huge! I am going to start checking the color of the wires in the morning. The 86 used the medium sized cap with coil in cap. I am going to see what those wires should have been. 86Z I really appreciate all your help. I drop a new post tomorrow afternoon to share what I find out and what the next step will be.

 

you'll probably find the extra wires are for the computer controlled part of the distributer.

 

he's not changing from car to tpi, he's putting tpi on the car

and if you take out the ecm harness you can separate the backup light wires and still have them.

 

OHHH crap. my appoligies . Im was so use to seeing TPI to Carb that thats how I read it. Ill go hide in a dark corner now

 

86Z I have been going through the wiring harness allday with the schematic and figured a lot out but I still have a few questions maybe you can answer. On the wiring harness I have a fuel pump switch connector; since we did not have an electric fuel pump before is there a fuel pump switch we need to add?

Also on the wiring harness behind the distributor there is a small connector labeled as a engine harness. 1 wire comes off of it and goes to the oil pressure switch. What do we connect this to?

Thirdly, at the end of the wiring harness by the O2 sensor connector there is a connector labeled Canister Purge Solenoid, I looked at my evap canister and there is no place for a connector. I did notice my canister is labeled Carb on top so I am thinking this must be changed out also. What is your take.

I appreciate the help.

 

Take a look at the drawing on my website under "links"
There is the schematic I did for my conversion of my 86' Monte. It has alot of info on connectors and some of the circuits you will find (like fuel pump and distributor)
Mine was a small cap, remote coil distributor and I had to add the high current pressure switch for oil pressure that runs my fuel pump.
It is setup for a 90-92 speed density so it may not all be what you need but has some helpful info anyway.
Jp

 

Here's a look at my transformation - ha ha





Here's the garage while doing this!

 

I did this swap back in 2001 on my 86 Trans Am.

I don't recall having to do much to the drivers side harness, I think I just tucked up all the wires I wasn't using.

The Pass side harness on my car carried the Speedo signal from the tranny which I happened to cut when I first went to a non-CC carb. I can't remember how the reverse lights were ran, probably in that same harness I cut.

This is what it looked like before I started,


and afterwards,


I had a lot of help from members here during the swap, as well as phone tech from John Millican (the one who does the LT1 intake conversions). He helped me out a lot and did the harness conversion from MAF to SD for me as well.

here is a vid of the car 2 days after I got it done and the exhaust installed, (you may have already seen it)
http://www.transamws6.com/video/ZepherWS6.mpg

 

Wow, that has some ***** to it. Obviuosly you changed out the cam. That looks much better with the TPI. Did you get rid of the emissions stuff or do you still have the evaporative canister? If you still have it I have a question for you. Thanks
Tony

 

well as far as the oil pressure/fuel pump switch goes, i have that as my motor was originally a tuned port out of an 88 formula, but i'll probably not use it, just bypass it, i wont be using the canister purge either, nor any other emissions

 

Gotcha, I just picked up the oil pressure/ fuel pressure switch with the brass tube from a guy on the board. The canister I also found on the board from a member with the correct connection for the purge solenoid. I am going to post a pic of something that is not described on the schematics near the fan relay. talk later
Tony

 

i started this swap as well today i have got the old motor(327) out and the new l98 in right now, i plan on starting my wiring this coming weekend sometime. one question i have is what is everybody doing for the speed sensor? also where is everybody locating the oil pressure switch for the computer and sending unit for the gauge

 

Ya, I had a cam, headers, 3" catback, and TPI heads on that LG4 motor.
I may have the purge canister from my 88 still, I took that out the other day.

 

i'm going to be using the stock speed sensor which is 2000 ppm with a 7730 ecm speed density, you change the wiring for the speed sensor to other pins, dont have that in front of me right now and make a change in the prom, i'll be burning my own.

 

I have the pressure switch for the fuel pump up on the top (drivers side rear) of the block.
The sending unit for the gauge is installed lower on the drivers side (about half an arms length down near the back of the block.)

there is a part number "4PAC" 4 pulse per rev that I used for the VSS from "jagsthatrun.com" , It is cable driven with the electrical output as well and bolted right into the 700r4. They can get you the trans gears so everything matches up nice.
The part numbers for the connectors (psi switch and VSS) are on the print on my site if you need them.

 

thanks i will look into that this week.