rspain85

I plan on going the megasquirt route for my build this winter, and I've looked around but havent found anywhere that just groups some good basic information about it. I thought a thread that groups Megasquirt info specific to thirdgens would be a nice sticky addition and a HUGE help to me and others like me who are wanting to get their feet wet and just need some basic info to get the ball rolling.

Pillsbry10

iTrader: (1)

http://www.msefi.com/index.php

rspain85

Quick question, diyautotune.com sells an adapter board for 86-89 TPI ECU's, but I have a 1992 Z28. Whats the easiest way for me to get megasquirt hooked up in my car? I'd like to keep the factory harness to save the hassle of re-wiring everything.

Pillsbry10

iTrader: (1)

the ecu's changed after 89 so the adapter wont work with a 92. however im thinking they might still have an adapter for that.

i have a v6 so i had to re-wire anyways and an adapter woudlve been a lot easier. if no else repsonds on this email diyautotune, they respond quick..maybe its just not listed on the site

rspain85

Hey man thanks for the reply. I'm pretty new to this, but if I recall i read somewhere that the speedo and other gauge functions are controlled by the newer ECU. With that said, if there is no adapter to buy off the shelf, I'm assuming i could cut the factory harness and wire the megasquirt to control the injectors and the ignition and leave the factory ECU to control what the Megasquirt wont do?

Pillsbry10

iTrader: (1)

i do beleive that is one option, depending on how much you spend the ms may be able to control it, the newer versions have a lot more options.

the speedo is an easy fix i just had to fix mine as it was controlled by the ecu. all you need is a buffer box from an 86 to 89 firebird(i think those are right years) and some wire. the rest of the gauges on mine work fine.

shoot them an email about what you want to do and they will get you the right MS unit

message project89 he might be able to tell you how to run both computers

rspain85

Yeah I guess i'll just email them and tell them what i'm trying to setup. I plan on buying the Megasquirt III and doing it right anyways. Cant wait to get started on this, should be a good learning process

Six_Shooter

iTrader: (2)

You will need to use a donor ECM to get the connectors you need for a PnP set-up.

I have made similar adaptors using donor connectors to go from '7747 to '7730, as a test, then just re-pinned in my case. I am also making an adaptor to go from a '148 to a '7730.

If you get the solder on RS232 style connectors, they fit right on the original connector pins, and give a solid connection. I have had some difficulty with just soldering the wire directly to the pin, since it's difficult to make a solid connection that way.

The MS3 is the only MS I would ever consider using, but I have had great sucess with the OEM ECMs.

FWIW, diyautotune is great to deal with, I've bought a couple things from them and it was easy, with quick shipping.

Matt Cramer

We have a box with the two black connectors on it that could be used to make a patch harness on a '92, but you'd still need to get the yellow-green connector out of a junkyard ECU. The box uses a PCB that you can solder the wires to, instead of soldering directly to the ECU connector.

Pillsbry10, thanks for the information on the buffer box. I'd previously been recommending one of Dakota Digital's speedometer controllers, but that would be a lot cheaper.

Pillsbry10

iTrader: (1)

Hey no problem, the only issue with that is as far as I know there isn't an aftermarket version of the buffer box. So salvage or eBay is your only option. The late 80s firebirds have them and the 90-92 tbi camaros have them

Six_Shooter

iTrader: (2)

There are other vehicles like some S-10s, and Astro vans that also have them.

There are also two different versions.

One is called a "buffer box", and this is the less desirable one, while it will work to run the speedo and such, it's not adjustable. There is a newer version called a "DRAC" (Digital Ratio Adaptor Controller) module, that can be calibrated by cutting or shorting certain jumpers on the board, or by installing a PC mount DIP switch set, you can just flip some switches to calibrate it.

You can find plenty of information obout these via a search engine.

Ronny

iTrader: (1)

you may wan to check with.... eficonnection.com. Member S10wildside is owner. they may have harness to MS adapter?

Drac0nic

My DRAC was solder only just FYI. I think this is consistent. I have heard of people doing this in the past however.

My personal advice would be to repin to an earlier ECM setup. It's fairly easy to do just have to keep track of which wires are which. Get the diagrams and look at the differences, preferably make a spreadsheet or other chart on it. I did one this way for a 1227148 box to hook into a harness that originally had a 1227747 on it. It was about 15 wires in all that were different including 4 injector lines I ran. The way I did my first MS2 was I used terminal strips so I could disconnect the ECU I was using at the time and switch back to a stocker if need be. If you're planning on doing a custom engine that needs tuning/ECU at the same time and don't have any sort of a tune for your stock box I would be a lot less inclined to sweat it.