Parallel-wiring MS
 

OK, this is a total newbie thread, but I've tried searching around and a lot of the answers are a bit cryptic. I'm pretty sure some of you have used vampire clips to tap into the OEM inputs and then used bullet connectors to replace the stock outputs on the ECU to allow the MS to just control spark, fuel, and idle. Can anyone post pics of their setup? Is it easier to order a Boomslang harness and then tap into that rather than hack up the OEM wiring? Am I on the right track? I am looking to make this sucker as plug and play as possible for as cheap as possible.

Just unhook the outputs for the injectors and the spark and plug MS into them. I personally would let the stock ecu do the idle if you are going to run parallel.

I made my own harness from ecu connectors, but it is identical to the boomslang with my own MS harness spliced into it. I made it because I didnt want to cut the stock harness. So fuel and spark are really the only things you NEED.

You can pull wires out of the stock harness terminal. Each terminal has 2 hinged doors, one top one bottom. The release latches are on the sides, slip your thumbnail in, and the hinge will open to reveal the terminal pins. Use an opened paperclip to push the tab on a terminal pin, and the wire will slide out. When you have all the wires you need removed, close the hinged door.

If you ever need to go back to stock, you open the door up again, and slip the wire back in. It's kind of a PITA to get the pin to catch into place again. Much easier to remove it than replace it.

Flyin Miata has terminal pins if you call them.

That's the kind of information I like to see. I was scared to attempt disassembly of my connectors and spent a long time repairing my harness this week from the prev owner destroying it. Glad to know I can always replace the wire in the pins if something is messed up.

It will cost you about $5 in wire connectors to hook up MS. If that.

damn, i think i'm the only one who just hacked up and wired in straight to my stock wiring harness. there's a sweet picture in my garage that gives you an idea how fun it was.
but my cas and injectors and iat sensor have their own harnesses.

Awesome. Just to clarify, aside from the pre-modded MS, the GM IAT sensor, and a serial cable, do I need anything else (aside from wire and connectors and crap)? I don't think I need a Stim because I'm not doing anything except hooking it up.

I'd offer to send you mine, but I am using it to troubleshoot this 2nd MS that I have that is becoming a HUGE PITA. How soon are you planning to do this?

I can lend you a STIM if you want to build your own and don't want to buy one. I'm pretty sure I'll be able to spare it in the next few weeks. I would recommend buying your own but mine wasn't much help. Once I knew MS was working I haven't plugged it back in since then.

Al, I did chop up my stock harness, cut the wires and crimped on bullet connectors. The whole boomslang patch harness just makes things easy/pretty/easily reversible to perfectly stock.

On the topic of wiring and harnesses does it matter where i ground my CAS seeing how I had to make my own harness for it.

nah, mine is grounded on the engine somewhere.
savington, you dont need a stim unless you're building it yourself

Thanks, glad to hear it cause that's how I did it.

I have a picture of a birds nest of wiring fun too. That's how I did mine. I like having an older car. I'm not afraid to hack it up. I am still tinkering with getting my idle to read correctly and then I will start trying to take control of stuff. Busy week at work with a MSM turbo upgrade in the shop, so I havent had time to work on my own car at all.

Good luck with your Megasquirt. Cool stuff.

not on your own mate, that's what I did too ;)

damn guys...I wish I knew wtf was going on lol, I need to tear into the stock ECU and figure out the best way to wire it...I def can not have a bunch of wires like that...x.X