Well i bought a MPGuino about 8 months ago when i first read about it and bought a civic vx donor car with no title. i've been searching for 8 months for a motor transplant recipient and finally found one. Its a 97 civic dx hatchback with ICE COLD AC.
First of all these 2 links are a great help
The Install Doctor - The Do-It-Yourself Car Stereo Installation Resource
that one shows how to remove the radio from many different makes and models.
Download PDF Honda | PDFTown.com
this one has many pdf's of factory manuals. Very important when finding wires.
So enough of the background info, onto the install.
DISCONNECT THE BATTERY!
Whenever i do something like this i research the wires and what needs to be done. After following the directions to get to the radio you will find this plug.
Shot at 2010-06-13
This is the plug i decided to tap into for always positive 12volt and ground. I prefer to do this because i just feel uncomfortable with pulling power or grounding with ecu wires. i'd rather just avoid any over-volting or some other bad stuff that is unforseen.
Next i got at the ecu plugs,
In the background you can see the pdf of the factory honda manual.
Pin 18 is for VSS, this can also be found from the VSS sensor on the trans, or at the gauge cluster, it is a blu/wht wire.
The top left 4 wires are all for the injectors, you only need to pick one of them for the injector pulse input.
Finally this is a picture of what i do when I tap into these wires. I put a damp towel that I don't care about under the wires, use those fancy wire strippers that grab ahold of one side of the wire and strip the other side, that way you don't cut the wire at all but instead pull the insulation apart in the middle of the wire. Strip the end of your other wire and wrap it around the ecu wire a few times, now solder. If you drip or drop the soldering iron or something weird happens you don't mess up the apolstry with the damp towel underneath.
After this, crimp your 4 wires onto the the 4pin floppy cable looking thing that came with the kit, MAKE SURE YOU PUT THE WIRES INTO THE PLUG IN THE RIGHT SPOT. Plug em in and they will clip in nicely. i never have done this before but it was very easy.
Read next post for some do's and don'ts.