MPGuino install on 97 Honda Civic DX

[steffen707]

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.

[steffen707]

DO'S
Always read the directions front to back and then read again.

DON'T
So after soldering all of my wires and running them to where I wanted to mount the unit, I tested the wires one last time. Turns out with the key on, my injector wire had power to it. Now I remember reading something in
MPGuino - EcoModder
about the wire you want from the injector DOESN'T HAVE power to it.

Upset that I did all this work I search over and over on the 1000 page manual to find out if that other injector wire comes into the cabin because I like to keep all my engine bay wires loomed up nicely. After not finding what I need I decide to tap into the other wire from the injector directly, i route it through the firewall inside one of the wire boots and connect it to my original wire that I have since cut off of the ecu injector wire.

Glad that I can finally get this project going I test the wires one last time. THE DAMN INJECTOR WIRE HAS POWER TO IT AGAIN. Now i'm upset and slightly confused, i thought the other wire was suppose to not be hot. I read the directions again on
MPGuino - EcoModder
and read that WHEN THE INJECTOR CONNECTOR IS UNPLUGGED, one wire is hot, and one is not. Turns out my original wire that i connected to from the ecu was the correct wire in the first place. After re-soldering my original wire back on, i put everything together and VOILA! It works.

[steffen707]

I was thinking of mounting this in a project box to a gps suctioncup thingy, but then i read somewhere that a guy had a problem with his overheating from being in direct sunlight, what are your guy's thoughts on this, and where did you put yours to avoid the sunlight problem?

[PaleMelanesian]

I use a Scangauge, but it too has issues with overheating in the Texas sun.

I use a windshield reflector when I park. That handles any daily driving issues just fine. If I'm driving long distances, I'll put a folded paper thing over top of it for shade.

[steffen707]

Calibration:
So at first i didn't know where to start so I looked at the wiki
MPGuino - EcoModder
and used the civic vx ppm and milisec/gal figures of

1994 Honda Civic VX 49-state 1.5L lean burn 5 spd manual 8208 0279235000

I zeroed my odometer, hooked up my garmin nuvi 765t and zeroed that out too, and zeroed the tank and current figures on mpguino.

I drove about 2 miles and calculated that the mpguino was reading the mph too low, with a rough calculation it was reading 2-3 mph under what my gps said at 40mph so this was about 4.8% too high. So i reduced the ppm from 8208 to 7801.

I then drove to gander mountain and back which was 54 miles exactly according to the gps, and 54.12 miles according to mpguino. So I did another calculation in that at 54.12 miles with 7801 pulses/mile, it read 422190.12 pulses, dividing this by the actual miles by gps of 54, I found a new ppm of 7818.335.

I plan to use this new ppm for a full tank of gas and then recalibrate a final time to zero it in perfectly.

What i'm wondering is this, do taller tires throw the ppm off? I'm guessing it must, but this is a common misconception about changing tire size and if it will throw your odometer and speedometer off, and I can never remember which answer is right. Somebody help?

[steffen707]

My initial results from the mpguino were awesome. This little device is really fun to play around with different driving. like in first gear floored i get 8mpg,in 2nd it gets like 15mpg at same speed, in 3rd 19mpg same 10mph acceleration, and 4th and 5th also go up in mpg as well. Now I gotta play around with from start to finish on a particular stretch of road, will i get better gas mileage accelerating moderately in a lower gear to cruising speed then put it in 5th and cruise, or will bogging the motor for a longer time at a higher mpg but for a longer distance then cruise at 40mph yield better results.

the cool thing with this device is that you can play around with all sorts of scenarios and trying new things out.

One thing i noticed is that under 40mph if I turned the ac on I would lose about 2mpg on the instant mpg screen, but at 70mph steady speed on flat road it made no difference, I would push the button in, and out and the instant mpg would stay the same. I was figuring id see like a 5mpg drop. Don't know if something is going on that I'm not understanding, but.....its interesting nonetheless.

[PaleMelanesian]

In general, lower rpm is better, down to the point where it can't maintain speed.

[nickdigger]

judging from your mpg, Pale, i guess you'd know Holy Cripes! Have you modded your engine at all, or is it all due to skill?

[PaleMelanesian]

Thanks.

The engine is stock. My mods are limited to a grille block for warmup and aerodynamics, higher tire pressure, semi-smooth hubcaps, and a Scangauge. That, and a LOT of adjusting that nut behind the wheel.

[Gas-x]

Your numbers are mind boggling! I love seeing 147.1% above the EPA!!!!!!