Few simple Lexus AFM questions

[jetjock]

It does not have the ability to make them equal. It can somewhat correct the mixture back but the system will still be out of balance. It's what drives Vf. Put your scope on it and see. Or maybe just stop over-thinking shit all the time. No wonder you get confused...

 

[CyFi6]

Or maybe just stop over-thinking shit all the time. No wonder you get confused...

How/why do you know that information then? Were you not "over thinking it" at the time you acquired that knowledge? Isn't knowing how it works kind of essential to being able to work on it/fix it? Anyhow thanks for that information.

Also on the topic of the scope, can you take a look at this maybe you will be able to give me some input on why my scope does this, perhaps its user error or just a POS?

http://www.supramania.com/forums/sh...ope-purchase&p=1915716&viewfull=1#post1915716

 

[jetjock]

How/why do you know that information then? Were you not "over thinking it" at the time you acquired that knowledge? Isn't knowing how it works kind of essential to being able to work on it/fix it?

Lmao. I rest my case.

User error and not just with the scope. Better towards the end though...

 

[CyFi6]

OK. The purpose of the video is to display the issue I am having with the scope not how to test an o2 sensor. Only issue I am concerned with in the video is why my scope gets laggy as time per division is increased. How can this be remedied?

 

[3p141592654]

Our ECUs do not compensate for ramp rate errors between rich-lean and lean-rich sweeps. The ECU does calibrate the cross-count rate, but not balance. Just the way it is, there is only so much you can do with a 12MHz clock and 12kB of ROM.

 

[jetjock]

How can this be remedied?

It can't. As I said, user error. It's a DSO right? Try using it as one...

 

[IJ.]

Our ECUs do not compensate for ramp rate errors between rich-lean and lean-rich sweeps. The ECU does calibrate the cross-count rate, but not balance. Just the way it is, there is only so much you can do with a 12MHz clock and 12kB of ROM.

Had to laugh at the earlier comment that a modern standalone will never be as good as the factory ECU

 

[Nick M]

The switching is to keep the catalyst in the proper operating range. The computer runs rich and lean on purpose for that catalyst.

I just wanted to repeat this. It didn't seem to sink in.

http://www.autoshop101.com/forms/h44.pdf

This is part of the OBD level 2 lesson, but it still applies. And as for Mr Icanoutdriveabs, if it really held at 14.7:1, then something was wrong. It is supposed to switch. The catalyst holds the fuel, then goes lean to provide the oxygen to burn off the extra fuel. It is supposed to switch back and forth, and it does it at a point that is close to 14.7:1, or 450mv on a DVOM.

http://www.youtube.com/watch?v=RR2KjnIXYNw

He tells you in the first 45 seconds why it switches, by design. And why most of you have wasted money with the A/F sensor that tells you 14.7 to 1, instead of a scoped voltage.