I am in the process of converting to carb from TBI. Soon I plan on wiring everything up and tackling the fuel system. Before I make that mess, I want to remove all the wiring that I don't need. It's getting in the way, it's an eye-sore and I want it gone. I know I can just leave it, but I don't want to just leave it.

I plan on cutting all the wires from that harness where they connect to the ECM, removing all the wire loom from the wiring under the hood, getting the wires as staight as possible, and pulling out the wires that were cut. (I will reorganize the wires and cover them with loom later).

Here is my question:

If I have removed the ECM and do not plan on using it ever again, does that mean that all the wires that are a part of the harness that was connected to the ECM are useless and my plan is feasible?

Any help is much appreciated!

 

Two things:
1) You don't need to cut the wires. They can be disconnected and removed in one piece.
2) Transmission TCC lock-up - it's part of the ECM harness. You need to hook that up one way or another. If you're taking the ECM harness out, you might as well leave it intact and buy a lock-up kit.

 

Thank you very, very much! I was actually unaware that I could pull it out in one piece. And naturally, I have more questions.

Are the wiring provisions for the temp sensor, A/C, electric fan, alternator, gages, lightning, basically anything that I want or need to keep that is necessary for the car to function (well) with the new carbed motor, are those wires also connected to the ECM harness? Will there be ANY wiring left under the hood if I remove the ECM harness?

Again, help is much appreciated!

 

Separate harness. Remove the ECM, pull the harness through the fender, and take it off the engine. What you need to run a carb will be left. Remember to change the distributor, b/c it has no advance and is computer controlled.

 

Thank you so much! ThirdGen.org is the shiznytes!

 

LET ME KNOW HOW IT GOES. I'M DOING THE SAME WITH MY 1982 CROSSFIRE INJECTED Z.

 

Will you retain the cruise control, rodrob? If so, note that the ECM grounds the latter, at least on Camaros (I'd guess 82-89). The following link should give you an idea:

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

Oh, in the first pic, note the blue and green wires. Back-up lights to the T5. Couldn't say if the wiring is different for other trans or not.

JamesC

 

Alright, I'm almost finished with the harness removal. Tomorrow I am going to start going through the wires that are left, identify them an get everything organized. I'll give you some tidbits of my experience removing the ECM harness, however, I am working on a 1991 Formula TBI so I don't know how much of this will apply to your Crossfire Injected Camaro. Removing the ECM harness is not hard, though it does take patience and attention to detail. The harness doesn't come right out. There is quite a bit of loom and electrical tape. The ECM harness and other wiring harnesses are routed together in the same loom throughout the engine bay. I was told that I shouldn't cut anything, but I found it much easier to cut the ECM harness wires at the fender and go from there. After cutting the ECM harness wires, I removed the tape and loom a little bit at a time and traced the wires to the different connectors, pulled them as straight as possible (as opposed to trying to remove them as they were, routed to their respective sensors, fuel injectors, etc.) and removed the wires a couple at a time. Like I said, the wires from other harnesses are loomed together with the ECM harness so pulling the harness out of the fender and just popping it off isn't going to happen (at least it wasn't going to work that way for me). You'll find that a lot of the ECM harness wires and other wires coming from the firewall on the driver side that are going in the other direction toward the passenger side are kind of tangled. It makes things much easier, as you make progress toward the driver side of the vehicle, to keep pulling the ECM harness wires through the tangles to keep the ECM harness wires close together and not routed inbetween, through and around all the other wires. Tracing and removing the wires goes pretty smoothly until you get over to the driver side. At this point, it's best to have a wiring diagram because things get a little hairy. This is the part where patience is important because it's pretty tight in that corner where wires go in a few different directions, through the firewall, down toward the cruise control harware, etc., and up to those two relays (or whatever the hell they are) that are bolted to the firewall.

I hope this helps. I have never claimed to be anything other than terrible at dealing with wiring so if anyone has any gripes with what I just described, I apologize.

 

im also in the middle of my swap, is this the c100 plug? also does it need to stay plugged in? i know the larger side runs toward the front of the car and the smaller one runs toward the passenger side, what do they control???

 

TTT!

anyone have a diagram for these plugs??

 

The plug on the drivers side needs to stay. That goes inside to the fusepanel and stuff.
The ECM wire harness is on the Passenger side. That big loom that crosses your ACbox and shoots into the Pass fender will go to a plug located behind the Pass Kick Panel.

 

I have an 89 IROC with a 305 TBI... i'm switching to carb. I am doing the same thing, removing the ECM and wiring. I took the ECM out, and i've removed the loom on almost all of its wiring in the engine bay. I also cut the ECM harness off to help pull the wires through, working my way across the bay. I have noticed that some of the wires do not go directly across to one place, a few of them split off, and go not only across to somewhere on the driver's side, but also forward as well. So far I have left these intact, but can i remove them? One in particular is a tan/white wire for example. One or two of these wires also tie in to the group of wires that go to the fan, which i assume is power for it. What can i do about that? Thanks in advance for all of your help.

 

i just want to know where the (red arrow) side of the plug runs too... and the (other color) side goes to. basically i have the whole plug, left about 4"s of wire and snipped it. now i just want to use the wires i need.

so no diagrams or charts to what color wire does what?

 

1st, you're highjacking someone else's thread.

2nd, we said "Don't cut the wires."

 

Hey I wasn't trying to "hack" anything... I just had a relevant question, and figured that I wouldnt waste space with a new thread. I didnt know that posing questions along with someone else's wasn't kosher... still new to this. My apologies, I'll start another thread...

 

1. its almost the same subject

2. i didnt listen

 

THANKS FOR THE LINK. I HADN'T THOUGHT ABOUT LOSING THE CC AFTER ECM REMOVAL.

 

OUR HARNESSES MUST BE QUITE A BIT DIFFERENT. I GOT MINE OUT IN ONE PIECE WITHOUT HAVING TO CUT THE ECM HARNESS. IT TOOK ME ABOUT 2 HOURS THOUGH. THE HARDEST PART FOR ME WAS GETTING IT THROUGH THE PASS SIDE FIREWALL AND THE BODY INTO THE CAR UP TO THE ECM ITSSELF. I DON'T HAVE VERY MANY WIRES LEFT IN THE ENGINE BAY.

 

well i have a question i dont mean to hijack a thread or nuttin, but sumone mentioned getting a vacuum controled timing distributor, im just wonder what vacuum line you nered to hook to it, im in the process of removing my ecm as well.. and does any know where a step by step thread is to removing an ecm? i just dont wanna go in there and mess nuttin up, cuz the previous owner has cut most of the wires to the ecm im pretty sure, but im not 100% positive about it.

 

I am doing the same on my 88 iroc 305tpi to 350 "carbed" swap. I removed my ECM today and had the same issue. It was neccessary to cut a few tan/wht wires in order to remove the harness, they went to the fans, alternator, and fuel sw. And also a few orange wires and so on. Didn't go nuts like some of the others and only cut the few wires that tied the ecm harness to the plug at the firewall drivers side.
My questions:
1. I did cut loose the fuel relay so it could stay with the vehicle. Will I need this or should this stay with the harness/ECM. I am planning to use the exsiting fuel pump with a two way regulator to feed the carb?
2.Along with the tan/wht wire which I cut loose there is a plug coming from the ECM Harness that feeds the fans. Will I need to cut this loose from the harness or is there an alternative to connecting the fans.

Appologize if there are threads addressing this already but I have done so many searches and read so many threads combined with reading those damn schematics all afternoon so my brain is totally scrambled.
I'm sure I will have a few more questions along the way. Any info much appreciated!!!

 

Sorry about leaving this thread hanging. I ended going back to active duty and didn't work on my car much since I was away from home. My car runs and drives fantastically with the new carbed 350. I still have to get everything cleaned up, reroute the spaghetti wires, replace the wire loom, reattach two accessory brackets that were neglected by the mechanic (which caused the 6th rib on my belt to shred to pieces) and figure out how to make the speedo and tach work again.

Someone mentioned wires that split off in a few different directions. I highly suggest getting a wiring diagram so you can identify the wires. Get an account at AutoZone.com and you can search for diagrams for hundreds of different vehicles. The wires that split off and the wires that were so long that could hang out of the engine bay and touch the ground once they were pulled straight caused me quite a bit of concern as well. I was very skeptical about cutting them out and throwing them away. Just remember, the ECM is GONE and whatever that wire used to do, it will probably never do it again. Check your wiring diagram. If it isn't for something that you need to run the carbed setup, you probably will not need it.

Unfortunately, I had to pay someone else to sort out the wiring while I was gone. I cannot legitimately provide any more advice on the wiring.

As far as the rest of the conversion goes:

I bought an HEI distributor, an MSD 6A ignition box (which the mechanic cleverly hid somewhere, I still haven't found it), MSD spiral core wires, a Holley 650 DP carb, a Mallory three port fuel pressure regulator with return line port, an inline fuel filter, a thermostatic fan switch from Hayden Automotive, a Holley TV cable corrector, a torque converter vacuum lockup switch from TCI, a choke for the carb, and as I remember other parts that I needed I will list them.

The fuel pump was hard wired to the ignition (I don't like this, but that's the way the mechanic did it and it works for now), the alternator was converted to one wire.

This is not a hard conversion, but it takes time and $$$ if you want to do it right. I spent more money on the conversion parts and the labor to install them than I did on the engine build.

 

Don't mean to hi-jack but does any one know what wires I need to run the buffer box run to control my speedo and such. I removed the ECM and what not. Thanks