C/L WB/WOT OEM ECUs...

[nacelp]

Like anything electricailly "smart" you MUST remain in control.  That is be
aware of your monitoring.  No one item, in your tool box is the end all of
engine mangement, or diagnostics.  If some thing is going wrong, very
*rarely* is it an *instantaneous* failure.   If the sensor is starting to
fail, least every O2 I've ever seen, gives you some warning.  YES, level of
tune will shorten that warning time at WOT.  That's why a driver has to be
on his toes.
  Kinda brings a new level of cheating to the forfront also.  ie I can kill
an O2 sensor, hood closed and from several feet away, if the engine is
running.
  Like I have been harping about for almost two years now, use your bargraph
O2v monitors as an ****indicator***.  Use LEDs to give you a rough estimate
of what is going one.  Have a EGT or some second monitor.  If you can't
watch an EGT and LED monitor, to prevent a misQ'd O2 well, then there are
other problems (no flame meant), just stating that you have to be in aware
of your environment, and in charge...
   The Limp Home Devise is preventing the problem, ie the driver.  Yes, you
can set up a DC monitor and see if it's is abnormally short, but then to be
accurate that needs redundant.  So where do you stop, for ever one fault you
can find another, and probalby cone up with 4-6 failure modes, and by the
time you have redunancy for all of them you have really gotten away from
simplicity is the key to design.
Grumpy


> There have been a couple of stories of Fel-pro users having just that
> problem...I think I'd use the w/b to set my WOT fuel map, then run it from
> the tables most of the time.  That's what several FelPro users I know do.
> Kendall Frederick
> > Thoroughly appreciating this thread everyone but here's a
> > Newbie's question...
> > Is WB O2 closed loop control at WOT actually safe?
> > I was just thinking that any fouling and/or other malfunction of
> > the O2 sensor
> > etc could result in you going way lean under load with
> > catastrophic results...
> > I'm thinking that you would need to have a "WOT Limp To The
> > Finish Line" mode
> > so perhaps you shouldn't disable the open loop stuff...rather have it
take
> > over if WB O2 output falls out of a pre-determined range for WOT
> > or something
> > like that...
> > What say you knowledgeable folks?


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