I did some more reading and saw that mrfred and tephra showed that a 0-5V input corresponds to a 0-255 number. Therefore, 'x' in the equation is not a (0-5) number, but a (0-255) number. I used Tephra's formula as a baseline and created one based on the PLX boundaries....

AFR=2x+10 (x=0-5v)

ECU SCAN

AFR=2*[(x/255)*5]+10
AFR=10*x/255+10
AFR=0.0392157*x+10

or Tephra Version.....

AFR=0.03937*x+10

Wideband is now being logged correctly within ECU SCAN. I need to contact PLX to get some exact data points so I can regress the data to create a more accurate equation for PLX users.

I would say the actual work involved in this swap is minor, but the learning curve adds some time. I will do a writeup when all is done.

 

I spent today adding an additional ground from the PLX to the ECU chassis mounts. I also added the capacitor between the analog signal wire and ground to reduce noise. It appears to be logging very well and the new EVO Scan software is neat with the street dyno graph. Don't laugh at my numbers and keep in mind the car has not yet been tuned. It was good to see AFR's tapered from 11.8 > 11.5 until after 7k rpm where they dipped down to 10.9. I had TSCOMPUSA run log through virtual dyno.

 

Thanks for the help Tephra, I finally got the WB to read correctly through the ecu... I had to ground it to the same bolt as the ecu is grounded.

I will do the multimeter check too, but would I be checking it on the ecu pin and ground? That doesn't seem very easy since the ecu pin is installed.

 

Just make sure the 1/2/3/4/5 volt programmed outputs work...

 

my evoscan is not reading afr from lc1 , is reading without the first number , also the problem is on the accestuner race any help

 

First off, thanks to everyone who helped put this together!!

has anyone been able to get this working with the Innovative LM-1? I did the hardware/software mods over the weekend but I can't find the correct formula to put in evoscan.

I have my analog output #2 in LM programmer setup to spit out 0v @ 7.35 AFR & 5v @ 22.39 AFR, just like the LC-1. I've tried the formula mrfred posted on the first page, but the readings I'm getting are a good ways off of what my gauge is showing.

for reference; I have my LM-1 grounded thru the ECU, and so is the analog output 2 channel. So there shouldn't be any ground off-set since they're sharing the same ground... anyone have input/ideas?

 

first step.

verify you arn't getting ground offsets

1) use LMProgrammer to set a 0v signal on your analog output
2) log the voltage in EvoScan (Eval = x*5/255)
3) make sure its "roughly" about right
4) repeat from #1 in increments of 1v (ie 1v, 2v, 3v, 4v, 5v)

If you get the right volts but within say +/- 0.05v, then your good to go.

If its drastically off, then maybe the formula/memory address is wrong

If its a bit off, then fiddle with the ground more

Once you have got that working, then you can work on the AFR Eval

 

Ok, so if I understand correctly I should:

#1 - set my voltage in LM programmer to 0v = 7.35 AFR & 0v= 22.39 AFR
#2 - change my formula in evoscan to x*5/255 (should x be the voltage in LM programmer or just leave the formula the same no matter what voltage I assign to LM Programmer??)
#3 - log the WBo2 setting in evoscan and measure the voltage difference
#4 - repeat for 1 thru 5v

thanks

 

x is the variable that EvoScan is grabbing, so leave it the same formula for each test voltage...

yeh in LM programmer you want a flat line for whatever AFR is being put out...

basically you are telling the LM1/LC1 to output a flat voltage regardless what AFR is actually being recorded. This is a great way to make sure the voltage you are getting in evoscan matches the LC1/LM1.

If your voltage isn't right, then sure as **** your AFR isn't going to be right

 

cool. thank you sir, I will do this and report back.

 

I checked my outputs the other day, still about 0.24 volts off. I moved ground off of the ecu ground bolt of the tranny tunnel as I was noticing very bad idle/cruise gas mileage?

So what can I do to get this thing working correctly? I am thinking of using the pins in the ecu for grounding the LM1, any problems with this approach?

Thanks for all the help Tephra, I'm still not getting it though

 

have you tried going to the block for the ground?

does the LM1 have seperate grounds for the heater/system?

 

haven't tried grounding to the block, what would be the easiest way to do this?

They do have separate grounds for the system and heater. I have them both on 1 lug.

 

finally had a chance to log voltage in evoscan. I only did 1,2,3v because it was all the same, but I can go back and log the rest if need be.

@ 1v wbo2 was reading 1.039215 - 1.058823v
@ 2v wbo2 was reading 2.039215 - 2.058823v
@ 3v wbo2 was reading 3.039215 - 3.058823v

is that a drastic offset?

 

thats fine - means you are less than 0.1AFR out... (assuming you use the 10 -> 15.99 AFR range in LMProgrammer)

and it would read leaner than it actually is (i think)