MPGuino 92 VX
 

I would like to know a bit more about getting and installing a MPGuino for my 92 VX .
What can you tell me about cost, installing and setting it up in the VX .
I really appreciate any help or insight you may have .
Thanks in advance, Dennis

It's $55, you can buy it from dcb here on this site (search for the MPGuino threads), and there's a ton of info on here from others who have installed them. Basically a battery wire, a ground wire, a fuel injector signal wire and a speed sensor wire give it everything it needs to track your mpg. If you take a look at the MPGuino wiki link it has some basic starter input values for the 'guino that you can recalibrate as you go thru a couple tanks. Works like a charm once you get everything dialed in to your car's distance/fuel signals, you can easily track lean burn mode then.

thanks tim3058
I will read all the info and purchase a unit.

How will this track lean burn? Does it use the different injector pulse? Can it illuminate an "economy" light when in lean burn for swaps?

If lean burn is actualized by changing the pulse width of the injector, that will be reflected in the signal to the mpguino. There are of course other ways to modify the fuel delivered and I dont claim to know everything about every car.

There's a big jump in instantaneous MPG when the car is in lean burn. For instance my Civic runs around 35-40 mpg tops on the highway when its cold in the morning, that leaps to 60mpg the moment the car is warmed up and goes to lean burn mode. While in lean burn if you apply the gas while cruising there's a noticeable "step" in the MPGs from 60mpg back to 30-40 when the vacuum drops below 6in. (the lean burn threshold). Not sure if you could rig up a light bulb, I just watch the gauge when accelerating to keep it in lean burn.

bengry -

The MPGuino doesn't explicitly show lean burn (as in "You are now in lean burn mode"), but between the Instant readout and the seat of my pants, it's pretty darn obvious when I'm in lean burn mode and when I'm not. Basically, when cruising in 5th gear, I get show about 50mpg or more (usually more) on the Instant MPG readout when in lean burn, and I get about 30mpg or less (along with a noticable boost in power) when I'm not in lean burn mode. I rarely show an Instant readout between those two ranges (in the 40s, for example), so it's fairly clear (to me) when I'm in lean burn.

Knowing where those limits are really makes an amazing difference in the avg FE I'm getting now. I haven't completely calibrated yet, but since I started with the calibration numbers for the VX from the wiki, I think I'm relatively close... so preliminary results seem to indicate that I've improved FE by ~10% just by adjusting my driving style based on the Instant readout on the 'guino. While I can definitely feel my Maus going *out* of lean burn, it's often hard to tell when it goes *in* to lean burn... using the Instant readout makes it very easy to verify that I'm in, and let's me modulate the gas pedal to go up to the "edge" of lean burn without dropping out of it.

Definitely the very best FE mod I've made to my Maus!

awesome guys .. thanks for the info .. I should be getting my MPGuino soon I hope .. ordered it Jul 31

Got it today .. now is there any play by play for wiring on the VX .
I really don't have a good record on my other wiring jobs so far .. lol
I would really appreciate any help in finding the correct wires before i burn the car down.. lol.
Thanks in advance Dennis

I'll have to look tonight for the details, but it's pretty straightforward. All the connections you need are on the right side of the passenger's footwell (VSS, injector pulse from ECU, constant 12v, gnd from a 'test connector'). Get some 22-4 stranded speaker / security wire (22 gauge, 4 wire) & run it from right side passenger well to wherever you'll mount it, and I'll get you the info on the connections within the next few days.

NachtRitter I appreciate any help
Thanks all

I found what I think is the correct pinout pic .. .:FFS TechNet : OBD1 ECU Pin out Schematics :. .. but after that I'm still lost.

MPGuino connections
 

Hey WD40...

That's a pretty good reference, actually.

Hopefully these pics will help a bit too.

Disclaimer: I prefer reversible mods in general, which applies to electrical mods too. I particularly dislike those "splicing" clips which cut into the electric wires when clamped shut; I've had enough occurrences of those wearing through the wires completely over time that I refuse to use them anymore. And if I don't have to cut and solder, I won't. This approach may not be for you, but that's what I'm showing here.

First, ECU connections. I made the connections I needed for the 'guino directly at the ECU connector.

The ECU is to the right of the passenger footwell (assuming LHD of course). A bit of a bugger to get out so that I could get at the connectors, but it's doable. Service manual pics help:
http://lh4.ggpht.com/_e1PWzsTgbJw/TH...CULocation.jpg

After getting the connectors off, it's not too tough to figure out which connections you need, based on the images and wire colors given by the reference you linked to above. Each of the three connectors is a distinct size. For example, the VSS signal is included in the "B" connector, which is the smallest of the three. The VSS signal is at pin 10, and should be either yellow with a blue stripe or orange. In my case, it was yellow with a blue stripe (see arrow):
http://lh6.ggpht.com/_e1PWzsTgbJw/TH...WireDetail.JPG

BTW - I had a spare harness, which I used to get these pics rather than dissassembling my footwell again... hope you understand... :)

You might notice in the pic above that there is an open hinged 'cover' over the ends of the wires... I take advantage of the cover when I 'connect' my wires.

With 22gauge speaker wire, I can strip the ends, bend a little 'nub' into the exposed wire, and then shove it in with the needed connector slot (VSS in this case) (see the white wire in with the yellow with blue stripe wire):
http://lh4.ggpht.com/_e1PWzsTgbJw/TH...WireDetail.JPG

Then I can snap the 'cover' back in place which helps hold my wire in place:
http://lh5.ggpht.com/_e1PWzsTgbJw/TH...ireDetail2.JPG

I also used electrical tape to keep the added wire from pulling out any.

I'll leave the Injector Pulse connection as an exercise for the reader. You can use any one of the 4 injector signal wires, which are on connector 'A', pins 1, 2, 3 or 5. You only need one.

Next, constant power. There is a 3-pin Data Link Connector also on the right side of the passenger footwell, just under the glove box. There are two connectors under there; one is the 3-pin connector and the other is a 2-pin Service Check Connector. Service manual image gives you an idea of where it's at (ignore the text about the jumper wire; it's unrelated to this topic. It's the best pic I could find in the service manual that shows where this Data Link Connector is located):
http://lh3.ggpht.com/_e1PWzsTgbJw/TH...orLocation.jpg

And here's a pic of it in my car:
http://lh4.ggpht.com/_e1PWzsTgbJw/TH...0/P8290120.JPG

The connectors are hidden behind the panel normally. The two outside pins of the 3-pin connector are always live; black is ground and blue is +12v. They are protected by a 7.5Amp fuse ( I think it is ) which should be plenty for the 'guino. My connectors are a bit hokey; next time I hit the wrecking yard, I'll see if I can find a standard connector that fits the 3-pin so it looks a bit cleaner.

Let me know if that helps to clear things up or if you still have questions...

Awesome .. thanks for the pics and help NachtRitter
I will get on this ASAP
Hows the "aerocaps" doing?

Let us know how it goes...!

I do have updates on the serving tray VX wheel covers that I need to post... will need to get a few more pics and get them uploaded before I update my How-To... :thumbup:

Good Info.

Its alive .. wow what a difference to see where the mpg are vs a preconceived idea of where they are.
I did a 200 kilometer run that averaged 3.75 L/100 km. thats better then my avg of 4.3.
I drove 60 KpH for about 5 kilometers and achieved 2.17 L/100 km = 108.393817 miles per gallon .. thats nuts .. hope to get an awesome tank avg from now on.
Thanks for all the help.

Awesome!! Congratulations!

I know this is a lazarus bump but since I have a 93 vx and am having an issue with the guino I thought it best to keep all the info together especially since I used the instructions here. :)

The issue is that the guino is not turning on when using the data link connector +12v power (light blue wire) per nacht's instruction. In looking at the haynes/mitchell repair manuals it show the blue wire going into d7 on the ecu but I can't find out what happens inside the ecu.

Also according to those manuals, the data link connector center terminal (white/red) goes to the #3 fuse, driver's side fuse box. If I connect to that center terminal the guino turns on and works.

Can I just use that center terminal? Why would the outside terminal not be providing power?

Tia.
Dirm

NachtRitter can you confirm that positive from your diagram data link connector +12v power (light blue wire) powers up mgpguino