AFR measurement was Re: O2 voltages

[Dave Zug.]

Sort of on topic - What do you folks (if any) use to cut the threaded
section OFF the spark plugs so you can see the carbon ring? Are any specific
manufacturers plugs easier to cut (or pop off) than others?

Alot cheaper than a WB, and it'll have to do for now.


----- Original Message -----
From: Bruce Plecan <nacelp at bright.net>
To: <gmecm at diy-efi.org>; <diy_efi at diy-efi.org>
Sent: Monday, October 02, 2000 12:49 PM
Subject: O2 voltages


>
> These are my observations and first impressions, and as I distill things,
> and get more time with the WB I'm sure they will be revisited, and
expanded
> upon.
> One thing that I'm totally clear on now, is how useless the oem gm O2
> sensors are, for anything other then their intended use (as being rich /
> lean, switches).
> I was able to run the WB on several cars, with several different monitors,
> and watch the displays.
> With all the filtering averaging etc that the ecm and scanners do, there
is
> time delay from when an event happens till when reported, and datalogging
of
> what the ecm is doing includes all the filtering.
>
> What's this really mean?.
> You still need to know tuning, and tune up.
> When using the oem O2 for tuning, your quessing,    it will just
> ****reliably**** tell you something when there is a major problem, and
maybe
> the magnitude of problem, ie the oem sensor voltage dropped to .3v during
an
> event,   and the WB showed just slightly richer then room air!.  *****So*
> what* looked* like* a* reported* leanness* (with the normal data logging
and
> scanner) was* actually* an* ignition* event*....
>
> The actual output of the oem sensor is nothing like the output of the WB
as
> far as resolution of cylinder firings, as far as variance in cylinder to
> cylinder.
>
> I'd also wondered why GM went to watching crankshaft accleration rates
> rather then synching the O2 to cylinder firings, well the above covers why
> you can't do it.
>
> Oem ones work excelent for what they are designed for.
> WB's **can** be an excellent assist, to monitor trends in what you engine
> like *relative* to performance evaluations,  and report back to you what
the
> engine ****LIKES****.
> ie.  if it runs EXCELLENT (best), at 12.25 AFR, then you know, 10.75 is
just
> wasting gas.  Just getting back to doing what the engine *wants* rather
then
> you wanting it to run at xc.y:1 AFR cause that's what you think it needs.
>
> The old saying of speed cost money has taken on a new meaning if you want
to
> solely rely on electronics to avoid having to learn much about tune-up.
>
> Now, if ya think about the above, and how it applies to the world as we
know
> it many things get clearer.
>
> Hope ya'll find this as interesting as I do.
> I ya don't want to hear about it lemme know.
> Bruce
>
> --------------------------------------------------------------------------
--
> To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
>
>

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org