Understanding and setting up the MPGunio
 

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

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

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

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

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.

Great and again many thanks.

Rich

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

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

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.

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

It must have been reset somehow then. Is it hooked up to the car battery, or something else? And, are you sure you didn't accidentally hit 2 buttons at the same time? Pressing top and middle resets the tank data.

Did not hit wrong buttons, am have a slight problem with the battery, it would not start yesterday, just clicked so perhaps that caused a reset?

Rich

Yea, it's possible. Starting the car takes a huge amount of power from the battery, so if it drained all the power and couldn't keep the voltage up near 12V, then the MPGuino could have shut off.

Well it was below 10 volts so I hope that is what happend.

Well I am testing the battery and if it does not hold a charge it is a dead lead POS...

And I will need to reset all the tests.

Rich

I should be receiving a MPGuino by the end of the week! anyone have base line calibration info or know where it can be found? for an 1989 F150 4.9? I have all I need to hook up the pwr grd vss and inj just lost on everything else.

Well my 2000 4.6 uses Speed 16000 for the VSS per mile and
0,135,000,000 for mircosec gal.

That should get you going.

I think I posted the defualts and watch out when working though the screens you don't change any...easy to do if you hold the buttone split second too long.


Rich

Got it today Yippee lol. anyway having a few issues and Have a few questions...

first off it flickers when the engine is running, and it keeps reseting, Tomorrow I'm going to triple check all the connections and whatnot.

Mine keeps resetting the Tank miles...

I too will reconnect to see if I can lock it down.

Rich

WooT WooT :D Its good to go now. Just need to work on the calibration some more.

only issue is it doesn't pick up a speed signal till about 10-15 mph... maybe I need to clean the VSS.

I might try using the VSS on the rear axle, the one it's tapped into now is on the transmission right by the speedo.

Thanks again for an awesome product:thumbup:

OK Got it locked down now.

OUCH Spoke too soon...

Switch to the Tank Big MPG readout and was driving and she locked up again.

I will now add a blocking diado and filter cap to the incoming 12 Volts.

The meter seems very senstive to voltage bumps.

Two things: a manual would be a big help, seems the trip miles reset with each turn on.

Which is what I am trying to do here, cover details as I learn them and pass them along.

The Tank miles are suppost to stay.

I had mine hooked up to a constant on 12 B+ on a relay I added to power up some add on gauges.

I am guessing there was some little backwards EMF coming off that relay.

Perhaps a little filtering to make them less sentive??

So I hard wired it driecly from the battery, same for the ground, it has not messed up for a couple of weeks.

So looks good.

So anyone done any thing with a TBI Motor like a Chevy 350 TBI??

Rich

I modified my version to save the Tank values if the vehicle has stopped for awhile, that way I've been able to take it out - reprogram - put it back in the car, and the Tank values are still there.

Also I'm trying a different calibration method in the software - so far not as accurate, but easier. When you fill the tank you write down the odometer distance and amount of fuel - then go into the configuration screens - they tell you Distance and Fuel amounts, if the actual amounts are different you input those values - the software recalculates the pulse counts itself. I'm thinking of putting this function as part of the Tank Reset, instead of in the configuration screens.

The reason for inaccuracy ... not enough digits of accuracy in the display, as compared to your calculator and using the raw VSS and uSec-per-fuel-unit values.

I will be trying it on a TBI Chevy as soon as I get it, just ordered it today. Have a 305 and 350 both :D

VERY IMPORTANT:

I still had a small touch of resetting, so with the advice of a electronic expert, I added a 100 MFD Cap across the power leads and I added a diode on the power in line, you cut the line and put the diode in line.

This stops all the EMF and backwards voltage that can happen in a car.

It has now held it tank records for 3/4 a tank, 269 miles...and mant stops and starts.

Rich

any luck with mpguino gauge with a 305 and 350?
 

Have you installed the mpguino on your chevy v8 engines yet?

Not yet been too busy.

Hope to do so soon.

Let me know how yours works out.

Rich

No I haven't, the weather has been very cold here and I don't have a shop. Hopefully it will get nicer here soon.

Now THAT is a good idea. I am about to order one of these, as I found values for VSS for my Dodge RAM. Still need to fiigure out the fuel use, but I am partly there. I am guessing you got this at Radio Shack? Thanks, Dave

Yes.

And it is still work AOK.

Rich