hold off, I think I got it working, post back after a quick drive

 

well it seems were back in the same place I started, tweaking the formula again to adjust for ground offset by changing from 9.6 to 9.4 gets me as close as I can get.

I guess its good enough for controlling closed loop cruise but not ideal for serious tuning.

 

Use the formula I posted in my last post, not the 9.4 crap lol. Its the most accurate you'll get with the ZT-2 analog.

 

I used that formula but on average the reading was high by .2 throughout the entire log. I lowered the offset to 9.4 which has made the readings more accurate. Must be because of ground offset.

 

You used this formula eval="((x*0.01895)*2)+9.6"and it was still off by .2AFR?? Thats odd, according to your entirrrre log it should be dead on for the most part. Can you do another log using that formula so I can take a look? I did notice oddball spots where it was off as much as .7AFR but thats where the analog noise and EMF comes into play.

 

If you look at dudical26's first AFR log that he posted, there is no consistent offset between the serial out AFR and the analog out AFR as read by the ECU. In general, it looks as if the analog out lags slightly behind the serial out. At any rate, the formula that dudical26 is using looks to be the best for his setup.

 

Do you guys think this would be close enough for use in replacing front and rear 02 signal?

When I tune I will use serial logging though. The analog feed will be convenient when we are finally able to log with openport 2.0 then I can log AFR to SD card without a lappy

 

Its fine for closed loop cruise. I wouldn't think once about it.

 

alright cool, that means it's time to deploy this closed loop patch.

 

Last night I got the ZT2 pretty darn close to the serial......let me know if you think something is off or im doing something wrong.

I used (19.6-9.6)/255 = .03922

Plugged it in as .03922*x + 9.6....it was about .1 afr off so I change the 9.6 to 9.7 and its very close. Final equation was .03922*x + 9.7, I have mine grounded to the metal shroud behind the glove box where the ecu is.

I am within .1-.2 at cruise which to me is more than fine....so tonight I will plug in the ML/BL and see how she works. Thanks for all the help guys....

This would be what I plug in, correct?

ML, 1/.03922 = 25.5

BL/ML, 9.7/.03922 = 247.32

 

As long as you get it close enough in the 14.0-16.0 range you should be fine. Whenever you datalog just use the USB digital signal.

 

Yeah that's what I have always done (even with the LC-1)....I use the serial cable to tune with and check if i want a accurate reading. I use the analog for wideband control and when im to lazy to plug the serial in and just want to ball park where I am AFR wise......

 

You got it.

 

Just tried it during lunch......car starts fine, starts to idle at 14.7 then immediately goes leaner and leaner.....it went to 20.1 and the car started to die so I shut it off, will just flash back to stock O2.

I dont understand? Im using the linear wire....the #'s log fine when comparing the analog to serial on the stock front O2, very close.

But something is missing to make this work....cause its not working

Here is the linear graph from zietronix website: http://www.zeitronix.com/Products/zt...bandoutput.htm

 

how long did it take for the car to go from 14.7 to 20?

I know that the zeitronix will not spit out any readings for the first 30 seconds while it "warms up" wonder if this is causing an issue during startup?