AFR

[Walter Sherwin]

If you are just trying to look for trends and patterns in OEM systems, then
by all means the OEM O2 sensor can do that for you.  BUT,  the best way to
view the data is graphically.  Forget trying to look at a little LCD number
in a tiny display.   What you want is an entire computer screen full of
graphical sensor data.

For instance I use a Snap-On MT2500 Scanner, and their software program,
which allow a person to view the O2 signal (or any other) on an entire
laptop screen.    This quickly and easily points out a lot of the features
of the control system in question.  You can pick up on the closed loop O2
frequency,  the AE enrichment (or lack of), and any other anomalies just by
examining the data patterns.

This is also the easiest way to identify "glitches" in any computer sensor.
When a glitch occurs, you can arm a Movie Feature and then playback the data
once you have safely pulled over to the side of the road.  Usually the
errant sensor, or at least a hint, pops out at you.  Other scanner companies
offer similar products.

If this sounds interesting then stay in touch.


-----Original Message-----
From: Geoff & Sue Richards <geoffsue at one.net.au>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Monday, November 09, 1998 3:07 AM
Subject: Re: AFR


>
>
>>Just nothing lasts forever.  Trying to survive in an exhuast stream
>>is a terribly rough life.  With the impurities in the fuel, atmospheric
>>conditions, you would be hard pressed to invision every possible
>>contamient.
>Yeah understood,
>just thought that 500 hrs wasn't real long for
>expensive tool
>>
>>>Are O2 readings good enough indication of how engine is running?
>>
>>If you talking about a oem 1-2-3-4 wire one, you'll eventually melt a
motor
>>down.  Things are worth doing right, or not bothering with at all.  If ya
>>wanna get by with playing games, fine, but there are
>>penalties for cutting corners.
>
>Sorry, I shoulda been more specific
>My main interest at the moment is learning how the different components
>work together,what happens when this changes etc
>So I am just WATCHIN' via scan tool on standard systems so I can learn
>what ta read when customer says flat spot etc only happens once every
>blue moon
>Changin' parameters is way over my head at the moment,if and when
>I get there I will do things right as you suggest
>but for now I'll just lurk inside my ECU  ;-)
>Thanks
>Geoff
>
>