MPGuino release one workspace

[njakts]

Hi! I had mpguino in my car long time ago then I removed it and now I tried to put it back in and run on some problems.
My mpguino now causes misfire when i connect it to car. Wiring is the same as before and it run without problems. Vss works normal, but as soon as I connect inj, idle gets rough, I can smell gas and got CEL and codes - random cylinder misfire on 1. and 3. cylinder... I am pretty sure wiring is correct, only differences are - I built a stand alone circuit refering to this diagram - http://opengauge.googlecode.com/svn/...no/mpguino.png and intead on using 50k resistors I used 67k and 1/4w zener diodes which are smaller then those I used before. What could cause these problems?
I googled around and could not find simmilar problem.
Vehicle is Lexus, so basicly a Toyota...
Thanks!

[AndrzejM]

Check if you connected (soldered in) your Zener diodes corectly, and if those resistors you've used are really above 50kOhm. It seems that you are giving falze zero signal to injestor and it stays opened. That's why you get missfire, and you can smell gasoline.

[njakts]

Originally Posted by AndrzejM

Check if you connected (soldered in) your Zener diodes corectly, and if those resistors you've used are really above 50kOhm. It seems that you are giving falze zero signal to injestor and it stays opened. That's why you get missfire, and you can smell gasoline.

You are right!
I figured that out myself on my way home from university
Zener diodes were soldered in parralel with 50k resistor (67k in my case, just double-checked)

Should work fine now.
Thanks!

[Hilly-Billy-13]

Originally Posted by FalconFour

^ Actually, you'll want to use this code instead: http://opengauge.googlecode.com/svn/...no/mpguino.cpp
I don't know why the "PDE" file stays up on the SVN page, it's moldy-oldy and faaaaar out of date. Now that everyone with an Arduino is using the (now-)standard '328 chip, there's zero concern of optimizing bytes in the compiled code... so the ye-olde PDE version should just be taken out back and shot, IMO.

Only thing you'll need to do is adjust the timing values (commented out) in the cpp version, if you're using a 16MHz Arduino as opposed to the 20MHz crystal in the prebuilt MPGuino board. Near the top, look for the section that says "//use with 16mhz, not tested" (it works fine). Match up the commented-out 16MHz values with the active 20MHz counterparts, and swap commenting ("//") on them, and you'll have 16MHz timing. Otherwise everything will be incorrectly displayed and timed on a 16MHz board.

Of course, over the next week or so I hope to start work on gutting and rebuilding MPGuino's code from the ground up, so this may not be too relevant in the near future...

I'm working on a version for the older European Diesels and have a couple of questions they relate to the pulse info from the fuel flow sensors. It's been noticed you can't do a good instantaneous flow from just reading & subtracting the pulses. It looks like you need to measure the time period between pulses from sensors and use that to determine your instantaneous flow rates. As I under stand the code this is how the instantaneous speed is determined. I also doubt you can use the interrupts from pins 4 for 1 sensor and pin 5 for the other, as the interrupts may hit at the wrong time. what's your opinion

[bobale]

Guys, how can I make MPGuino round all values to only one decimal? I've found format function, but I'm not sure how to modify it to give only one digit precision after decimal point.

Any help is appreciated.

[bobale]

Anyone?

[Davinator61]

Originally Posted by mosier

dcb:

What method did you use to calculate your microseconds per gallon?

For a DOHC Saturn, with 21lb/hr injectors I get

21.00       lbs/hr
6.25        lbs/gal gas  (~72 deg F gas)
3.36        gal/hr
17.86       minutes/gal
1,071.43    seconds/gal
1,071,428,571.43	microseconds/gal  per injector
267,857,142.86          microseconds/gal with 4 injectors?

Fuel temperature will have a big impact on the calculation, I wonder how scanguage or oem systems handle this (ignore it?).

I just put in my order, and hope to get it running on my non-obdii SL1 pretty soon..

I tried your by-hand formula versus the Excel Spreadsheet calculator posted on the Ecomodder.com Wiki, as applied to my 1991 Jeep Cherokee Laredo 4.0L Inline-Six engine, and found two different numbers as a result, with a variation of 7,894,737 between the 197,368,421 as done by hand, versus 189,473,684 as calculated by the Excel Spreadsheet calculator.

My advice, in this case, would be to try each of both numbers, first the low, then the high, then adjust incrementally by around 5-10% of the difference (193,421,053, in my vehicle's case) until you find the actual "Sweet-Spot" for accurate fuel consumption numbers. I have found my MPG numbers are POSSIBLY off by as much as 10-15% or MORE when just using the Excel Spreadsheet calculator's number, otherwise. Hope this helps, even if only a little...

Edit: Just tested out my theory, based on the two calculations and found that also dropping BELOW the lower calculated Microseconds-per-Gallon by the calculated difference between both numbers MAY also have a positive effect on accuracy of the Microseconds-per-Gallon equation. More testing AND re-calibration of the MPGuino will be necessary in order to confirm this, of course.

[stewie]

Originally Posted by Yoshi

Just FYI...
I would like to explain how fuel parameter is set for Honda VX on my SuperMID.
MPGuino release one workspace - Page 9 - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

I use the fuel parameter 14220 for Honda VX.
The count tick is 5 usec, therefore the 14220 means 71100 usec per 1 milli-liter fuel usage.
Please note that I subtract 100 ticks (500 usec) from each injector on time for the mechanical delay (injectorSettleTime on your source which never been used).
so...
71100 usec/milli-liter -> 71100 X 1000 X 3.785 = 269113500 microSecondsPerGallon

Regards,
Yoshi

Thanks Yoshi for that setting. What are rest of the settings suppose to be set to? I got finger happy and changed some by accident when i got it like delay of injector etc. Can you provide those as well please. Also are rest of the settings car specific. Also if anyone with HOnda Civic VX can chime in and fill in the blanks that would be good. Thank you in advance.

VSS PULSES/MINUTE = 8208 per wiki page

Microsec/Gallon = please provide yours and why is yours different? Using Yoshi of 269113500

Pulses/2Rev = 1 per wiki

Timeout =

Tank Gal = 10000 (mine tank always seems like 10 gal)

Injector DelayuS = ???????????????????? PROBABLY IMPORTANT

Weight (lbs) = 2094

Scratchpad (odo?) = what is this?

VSS DELAY MS = ???????????????????? PROBABLY IMPORTANT

INJTRG 0-DN 1-UP =???????????????...WHAT IS THIS? PROBABLY IMPORTANT

Also what is the difference between current and instant mpgs screens?

[94-turbo]

I just received my MPGunio!!! I need to install it into a 1994 gmc k2500 turbo diesel.
It uses a PMD, pump mounted driver that uses pulse width to vary injector output. It controls All 8 injectors so I'm hoping the MPGunio can handle that many pulses vs 1 per cyl
Also, has Anyone connected a MPGunio to a gm pickup speedo...and if so what settings? I'm glad there are still those that know these units inside and out!

[AndrzejM]

Congrats! You'll love it like I do I'm totally in love with my MPGuino

Anyway - you don't need any specific settings for your car to make your guino working properly in virtually no time. I've explained the procedure to Stewie here MPGuino calibration procedure. Feel free to use it
And please share your experience with installing guino in your diesel!
Good luck