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-   -   Output voltage O2 sensor (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/output-voltage-o2-sensor-288742/)

mr_vaughn 03-30-04 01:51 AM

Output voltage O2 sensor
 
What is the voltage range of the Stock O2 sensor??

I am going to get an LM-1 Wide band sensor that has an output option that allows you to have a voltage output for AFR gauges and ECU input..

I currently have an Auto meter AFR and found out that
Lean Range Four red LED’s (.050 to .249V)
Stoichiometric Range Ten yellow LED’s (.250 to .749V)
Rich Range Six green LED’s (.750 to 1.000V)

If the stock is from 0V- 5V this would explain why the AFR gauge always bounced around....

the wideband is going in with 2 x 720cc injectors and a Black S-AFC 2

J-Rat 03-30-04 02:10 AM

Dude, there was a HUGE debate about this a year or so back.. Starring our own special guest, HAILERS. Wonder if I can find it..

J-Rat 03-30-04 02:15 AM

https://www.rx7club.com/showthread.p...Sensor+Voltage

http://hp.autometer.com/techtips/faq...ignitions.html

NZConvertible 03-30-04 04:11 AM

All narrow-band O2 sensors are 0-1V, including ours.

An the A/F gauge is supposed to bounce around. If you don't understand what you're seeing, a wide-band isn't going to be any use to you.

HAILERS 03-30-04 08:31 AM

****If you don't understand what you're seeing, a wide-band isn't going to be any use to you*****

Everyone has to start somewhere. It wouldn't hurt to read the AutoMeter article on 02 sensors though.:cool:

Josepi 03-30-04 08:45 AM

It'd be nice to see a graph of AFR in relation to voltage for the stock O2 sensor. One thing I do know is the LM1 only has 2 points in which to specify voltage to AFR. I'm unsure if it makes a sweep or only outputs three values on the simulated narrowband output.

One of the reasons I'm holding off on buying a WBO2 sensor is that specific reason. I need something that ACCURATELY mimics a narrowband O2 sensor so I can just use my LT-8 datalogging more effectively.

HAILERS 03-30-04 10:19 AM

****It'd be nice to see a graph of AFR in relation to voltage for the stock O2 sensor****

I don't think that is possible since the narrow band is soo inaccurate at anything other than stoic. If it were not inacurrate at other than stoic....then we wouldn't be buying wideband monitors. You've got a long wait, from my understanding of narrow band sensors. I could be wrong. Don't think so though.

NZConvertible 03-30-04 04:12 PM


Originally posted by Josepi
It'd be nice to see a graph of AFR in relation to voltage for the stock O2 sensor.
Ask and you shall receive. ;)

https://us1.webpublications.com.au/s...6/0618_4mg.jpg

You can see how the sensor clearly shows whether the mixture is above or below stoichiometric (which is all the ECU wants to know), but isn't very good once you too far from that point.

Lots of good info on O2 sensors in this article. Everyone should read and learn.

Josepi 03-30-04 04:22 PM


Originally posted by NZConvertible
Ask and you shall receive. ;)

**huge pic**
You can see how the sensor clearly shows whether the mixture is above or below stoichiometric (which is all the ECU wants to know), but isn't very good once you too far from that point.

Lots of good info on O2 sensors in this article. Everyone should read and learn.

:bigthumb:

Guessing this is why my current narrowband input on my LT-8 reads either 13.7 or 14.5 :o: ...

I have seen it dip into the 12.x region!

mr_vaughn 03-31-04 12:35 AM

the idea i had was to use the wide band and replace the narrow band (stock) and use the output of the LM1 to place the corresponding voltage for begining and ending values with the Bosch sensor 11027 output levels to the ECU with

0.05V @ 1.2 Lambda
and
0.95V @ 0.8 Lambda

it will not correspond to the graph shown in this post but would rather be a straight line from either points on the graph...

found Bosch 11027 outputs here
http://www.buckeyetriumphs.org/techn.../AFMonitor.htm

HAILERS 03-31-04 08:12 AM

About that graph..........IMHO/IMDO, that shows how useless the narrow band is.

Watching a wideband, while the stock ECU controls a virtual stock 87 turboii, the stock ECU will make the afr go way down in the low 10 range under full throttle. You ain't a gonna see that with a narrow band. Trends...yes. Accuracy, no.

I'm not into trendy things. I watched a digital meter in lieu of a afr meter for a couple of years. Ain't a gonna go backwards no more.

The TechEdge 2.0 wideband will deliver a simulated 02 sensor signal to the ECU if you arrange it to do so. It's an option of the device along with logging. http://wbo2.com/::p:

NZConvertible 03-31-04 03:29 PM


Originally posted by HAILERS
About that graph..........IMHO/IMDO, that shows how useless the narrow band is.
This statement is incorrect. What you meant to say was "that graph shows how useless the narrow band is for tuning". That does not make it useless. ;)

fstrnyou 03-31-04 07:00 PM

by that graph, and the graph that came with my defi' meter....
when the guage says lean, you're definately lean,
and when it says rich, you're definately rich,
and any other point on the graph, the ECU doesn't have a clue what the AFR is.

NZConvertible 03-31-04 10:55 PM


Originally posted by fstrnyou
...any other point on the graph, the ECU doesn't have a clue what the AFR is.
Correct, and nor does it need to, a point many don't realise. Closed loop operation is simply the ECU adding fuel until the O2 sensor reads richer than stoichiometric, then pulling fuel until the O2 sensor reads leaner than stoichiometric, then repeating the cycle rapidly.


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