Hello everyone,

At the moment I found a good deal on an s4 TII engine that would go into my S5 vert. I posted up a thread in the second gen section about questions when wanting to use the whole complete s4 TII engine without switching sensors and what not. It seems if I want to go this route I will have to use a stand alone to make it easier for me, if I do decide to get the S4 TII though...

I have used a megasquirt system in the past, but I have never wired one up to a car. I was wondering how some of you guys wired your megasquirt, not using the existing harness, but making your own custom harness and running fresh wires. Will the old front and engine management harnesses be completely eliminated or will I have to keep some of these. If anyone can link me to some good information on someone who has wired a MS on a second gen i'd really appreciate it.

Thanks

 

When I did it I completely removed the entire factory wiring harness and used my own. Then again I also removed EVERY factory wire from the entire car and redid the whole thing from scratch!

 

As far as the sensors go, do you reuse the plugs off the harness for them and wire back to the mega squirt? I'm trying to get an idea how this will all go....

 

when I did mine, i pulled the existing emissions harness out of the car (if you have one that comes with the engine, then use that), inspected all of the wires, and replaced the bad ones. Then I wired each of the wires from the emissions harness directly to the DB37, although if I were to do it again I'd try to re-use the stock ECU connectors if they arent in terrible shape, and just make an adapter harness that goes between the ECU plugs that you de-solder from the ECU and the DB37 for both the connections to the emissions harness and the main/cabin/interior harness. As long as you draw it otu and document it, its pretty easy to keep track of, and it removes all of the problems with using an out-of-series engine in an FC.

When you replace wires, make sure to replace them with ones of different colors, cause you're going to hate yourself trying to troubleshoot something if you have 20 red wires in a harness. DIYautotune offers a harness kit that you'd use to connect to stock plugs and has a DB37 on the end, but keep in mind that you need to connect to two wiring harnesses from the ECU, so you'll either need to make them one giant harness or pull apart the ECU and use the plugs from there anyway.

 

Thanks for the answers, I have a good idea as to how the wiring will work now, by the way I decided not to go with the S4, I have a better project in mind now : )