Understanding and setting up the MPGunio

[racprops]

OK Love the MPGunio, so much I have ordered four…

But I am going cross eyed and nuts trying to figure it out.

Sorry but I have read a bunch of threads and the pages on MPGuino - EcoModder

But as I have worked though some of the old threads I find what I just read to be old news, like the pre-loader that is no more…wasted my time there...

So I am asking for a break down on the now current system.

Here is one that is nuts, I am told my Ford uses 8000 pulses per mile but when I input that into the MPGunio I get readings about twice as fast that the speedo…But cut them to 4000 and it is even farther off.....????

On wiki it said to correct the miles driven, but what there is only the pulses per mile screen, so I am at a lost how to correct the miles driven, did I miss a screen?? (The Zemco supplely let you correct its read out, drive 100 miles and if it said something else you just input the corrected miles driven and it was now programmed.)

And I am still trying to get the microsec/gal setting right…. (I fear that some of the other settings have to be right for this to work, right??)

And there are all the other screens in set up, please tell me what I should do with:

Pulses/2 revs
(I have a Ford that fires each injector for its cylinder, a sequencer system so it should be 1 injector per rev, right?? And say 2 or 4 for my Chevy TBI?? Or what)

Timeout/microsec… Back light goes off, readouts stay on??

Tank Gal, (still not used?)

Injector delay US (What is default and what would you suggests on my cars?? Oh I have a 91 Toyota too)

Weight (LBS) (used/not used?)

Scratchpad…(what is this)

VSS Delay (Default…? Suggestion settings please..)

Injtrg -0 DN 1-UP?? (What is this: dn on dropping wave or up for rising wave from??, Or leading or following edge?? Does it matter?? Suggestions??)

Thanks for a great little unit.. sorry to bust your chops but I really need the up to date data to set this up to work on three cars…

I felt these answers were on such a need by others I put this on the site.

Thanks.

Rich

[moorecomp]

On the mgguino wiki, the only 2 Ford cars in the list of settings are using values of 15800-15900 for the pulses per mile. All of the data I found on the internet regarding what the pulses per mile value is for my car, all said 8000, but 15900 is dead nuts. My mpgunio is very accurate in the miles driven. Typically on a 400 mile tank, it will be within 5/10th's of the odometer reading. The ms/gal is a little harder to get just right, but most of that has to do with innacurate fillups. Mine has been within .2-.4 gals on a typical 10-11 gal fill. All of this is covered in the calibration link on the wiki.

MPGuino - EcoModder

[racprops]

Thanks, So it is nearly double the factory setting...

Roger on that.

I have been compairing the Gal per Hour read out to my scan gauge GPH and trying to match it, as the scangauge is accurate as long as everything is stock.

Any idea what to do with the rest of the screens/setups?

Rich

Originally Posted by moorecomp

On the mgguino wiki, the only 2 Ford cars in the list of settings are using values of 15800-15900 for the pulses per mile. All of the data I found on the internet regarding what the pulses per mile value is for my car, all said 8000, but 15900 is dead nuts. My mpgunio is very accurate in the miles driven. Typically on a 400 mile tank, it will be within 5/10th's of the odometer reading. The ms/gal is a little harder to get just right, but most of that has to do with innacurate fillups. Mine has been within .2-.4 gals on a typical 10-11 gal fill. All of this is covered in the calibration link on the wiki.

MPGuino - EcoModder

[racprops]

Double the factory setting does the trick... I think these are seeing both the rising edge and falling edge of the square wave and thus counting twice.

So double all factory VSS counts...

Now to get the rest done...

Wiki does not seem to cover those other screens...


Rich

[McTimson]

The main things you need to worry about are VSS and usec/gallon. If you can't get it pretty well calibrated by just those, then you can start messing with the other stuff.

Pulses/2 revs
-Default is 3, I wouldn't change it unless you can't calibrate the miles driven by just the VSS

Timeout/microsec… Back light goes off, readouts stay on??
-Yes, the readout stays on all the time. If the power is turned off to the MPGuino, it loses its' current and tank data, but will keep the usec and VSS settings. The current draw is very low on the MPGuino with the backlight off, but if the car is sitting for a week or so, I would disconnect it.

Tank Gal, (still not used?)
-Yes, still not used, as far as I know. It wouldn't be too hard to program in a function that implements it on the larger Atmega chips.

Injector delay US (What is default and what would you suggests on my cars?? Oh I have a 91 Toyota too)
-Default is 500, I would keep it at that unless you have some other problems with the gallons readout.

Weight (LBS) (used/not used?)
-Not used, could be used in the future for force calculations

Scratchpad…(what is this)
-Just something to note mileage, or some other number. It's not used, don't worry about it.

VSS Delay (Default…? Suggestion settings please..)
-Default is 2, again, I wouldn't mess with it unless you can't get the miles calibrated by just the VSS.

Injtrg -0 DN 1-UP?? (What is this: dn on dropping wave or up for rising wave from??, Or leading or following edge?? Does it matter?? Suggestions??)
-No idea.

[racprops]

Great and again many thanks.

Rich

[racprops]

OK what I found and could see was if I was a tiny bit slow on the center button, (like held it a split second too long…)when the screen changed it would/could also change the value of the number in the next screen.

This happened to me a couple of times so now having the known and correct default settings I could make sure each screen was set to the default.

So for 2000 Ford Crown Vics and Grand Marquis VSS is 15900 and a good starting point and near match to my scan gauge GPH idling is 013500000.

I will of course do a tank or two of gas and farther calibrate.

Rich

[racprops]

OK A new glitch??

Is this normal: I have been trying to calibrate the MPGunio, and thought I could drive it for a week and then correct the miles driven and MPG calibration…

But this morning I found all the read outs zeroed., No record of miles driven and no MPG tank.

Does these reset each power up? Does it only remember as long as power is on and driving is done and zero out each stop or power off??

OR is this unit also bad??


Rich

[McTimson]

The unit needs a constant power source in order to keep the current and tank values. The calibration data is saved when it shuts off, but the other values are reset. That's why you can't just wire it in to an accessory voltage source on the car, because those are only on with the ignition. It has to be hooked up directly to the battery (with a fuse, preferably), in order to function properly.

The power drain is very low - I left mine in a car for over a week last winter without unplugging it, and the car still started up just fine. If your car is going to be sitting for an extended amount of time, then it would be a good idea to unplug it, but if it's only for a few days, then it should be fine.

[racprops]

It is on a "on all the time power supply", but none the less it did not keep the numbers.

It did indeed remember the settings, but trip info is gone.

Rich