MPGuino installation/setup: 1998 Geo Metro (Pontiac Firefly)
 

dcb recently sent me a "care package" with a couple of components my small town rat shack didn't have. To my surprise there was also an "evaluation" MPGuino in the box!

I hooked up to the car (1998 Pontiac Firefly 1.0L TBI 5-speed) this weekend.

Random observations:

1) COOL!!!

2) finding the injector & VSS wires was easy, mostly because dcb has the same car as mine and has blazed that path already (with pictures!): http://ecomodder.com/forum/showthrea...html#post30667

3) with those settings, the MPGuino was showing half the MPH that the speedometer/ScanGauge showed, so I halved the VSS Pulses/Mile value in the MPGuino setup (to 8204), and that seemed to fix it.

4) I still need to factor in an additional offset for VSS Pulses/Mile, because the transaxle I swapped into my car (with a taller final drive ratio) was originally calibrated with a smaller tire size (diameter) than my tires.

5) The car's MPH display is jumpy, as dcb already noted with his Metro, though he also found that despite this, the total distance traveled seems accurate.

I was thinking I could calibrate my car's VSS pulses/mile setting by jacking up the drive wheels and idling the car in 5th gear to rack up some mileage without having to drive around unnecessarily. It seems to idle @ about 30 mph.

Any technical reason I shouldn't do this? (Aside from the fact it'll pad my tank MPG with some awesome numbers - seems to get about 150 mpg idling in 5th on jack stands. :p)

I probably won't have a chance to calibrate the MicroSec/Gallon until I get back from the tall ship race though, because I'll have to do some actual driving to tweak it.

I think it would be ok, and really neat to see. Just be real careful!!!!

IMO I would ask Johnny what he thinks...

You are running the Xfi transmission correct? So the vss pulses should be the same for mine right? Ordered my stuff today to make my MpGuino Iduino, can't wait real feedback finally.

And can you enter these numbers right through the MpGuino setup screen?

Nothing wrong with having the car securely raised and supported while you run it in gear at idle. This will make the axles have slightly more flex than usual, but it should be fine for a short period of time.

bbjsw10: I'm running the Swift 1.3 SOHC transmission, not the XFi.

Mullet: thanks for that. I will admit I suspected as much and went out and ran the "jack stands calibration run" before I read your reply. Stuck a snow scraper lightly against the gas pedal and accumulated 20 miles per the ScanGauge. That'll give me enough info to get the Guino dialed in (when I get back from my trip).

Cool, let me make a guess at your modified vss pulses per mile (stock *should* be 8208). Assuming your tire circumference is 5% greater than stock for that tranny, I will guess you have an effective vss pulses per mile of 7798.

Also will stash the metro install pics here till we get car specific wiki pages with setup data AND pics:

http://opengauge.org/diympggauge/metro1.JPG

http://opengauge.org/diympggauge/metro2.JPG

http://opengauge.org/diympggauge/metro3.JPG

Just a note
The injector drive wire comes from the ecm as well.
You wouldn't need to run any wires to the engine if you tap all of them onto the ecm.
S.

I've had mixed results tapping into the ECM for the fuel injector, would like to see someone actually make it work before calling that a certainty.

Worked for me - got Injector and VSS from the ECU...

How I collected my speed/distance calibration info for the Guino...

YouTube - Calibrating an MPGuino fuel consumption computer

Wow :)

I forgot to mention here, I added a metro specific wiki page (with an mpguino block):
Metro - EcoModder

I do think it would be more accurate to use the odometer, or the mileage posts if your odometer is off due to tire changes/etc. I've seen the SG come up short before and speedometers are notoriously off.

Generally speaking asian cars will be a multiple of 4104 and gm cars will be a multiple of 5000 though.

I "pre-calibrated" both my stock odo and the SG2 against Google Earth: http://ecomodder.com/forum/showthrea...uracy-110.html

I'll likely be home around the end of the week. Looking forward to finishing the setup & build of the other guino.

Any idea for VSS and Fuel setting for a full size Ford??? That is a 2000 Mercury, more or less the same as the Crown Vic.

I get a kick out how many small car people are fighting for more MPG...

I also get a kick out of my hot rod Ford with its 4.6 V8 that gets 29.8 MPG highway...

And averages 20.MPG City to the combo is say 24.5…

And I am also working on a 1993 Chevy Van with a 5.7 350 TBI V8 soon to be a 383 with TPI.


And anyone playing with Hydro and other things?

Rich