I have a 1987 Firebird. I need some advice for dewiring my engine bay. Can I bypass my ecu? If so will all of my gauges still work? I'm running a carburator and a manual trans. I want the simplest look possible. Thank you

 

First piece of advice to anyone planning such a modification is to scour ebay and pick up a copy of the Factory Service Manual (NOT a Chilton or Haynes any other aftermarket book) for your specific 3rd gen.

 

The above post is good (and necessary) advice. ECU and gauges are on seperate harnesses. Remove the ECU harness, and leave the other harnesses alone. The ECU harness comes from the passenger-side kick panel and routes through the passenger-side fender apron near the firewall into the engine compartment. It's best to remove it in one piece and not to cut any wires. Don't remove any thing from the driver-side...

 

So if I don’t plug-in anything and remove the ECU harness everything else will still work?

 

Follow wires to the end and if it isn't being used with your engine (plug is just hanging there) then take it out. Keep doing this and the harness that goes into passenger side fender will gradually disappear until there is just a couple wires left, possibly even no wires left. Everything is intertwined all over the engine bay so you'll find wires spliced into other wires that are still hot. Follow those wires too, you'll be surprised all the stuff you'll be able to remove.

It's hands-on work and takes a long time, I can't say just cut the whole bundle because that could maybe cause you problems. It's best to follow each wire by hand to see whether or not you still need it. That's how people avoid mistakes / problems.

 

Thank you . All of this information is a big help

 

Depending on time and your budget you could buy a used engine harness and make the necessary modifications then drop the harness in.
88-92 Camaro / Firebird Used Engine Harness, Select Application - Hawks Third Generation (hawksmotorsports.com)

 

Dewiring is fun for me. Get a factory paper manual and learn how to read schematics. The CD manual is cheap and works but I personally hate it. I'm currently in the midst of edelbrock fuel injection and Dakota /Hawks dash swap. The new gauges will save a ton of pain for me.

 

Thank you for all your help. Now I find that with "more information comes more questions". Before pulling out the 305 I labeled most things (wires) fairly well. I got that computer harness unplugged and out of the bird as a whole. What a huge difference it made. After bringing the computer harness into my garage I noticed 2 wires/plugs that I have labeled water pump and water neck. I feel like one of them is the sensor that kicks on the electric fan. In fact I purchased some parts this weekend from a guy with a similiar car and I saw that he didn't have sensors or wires going to the water pump or water neck. Unfortunately he didn't know much else but said that all of his gauges worked. So the questions: 1. What does each do? 2. Do I need them? 3. If not whats the fix?