Tom Slick North wrote:
> Computers do look at a range... if the computer sees the 02 sensor withing a
> certain range, it makes no adjustment for it, only when the O2 sensor goes
> above or below that range, does the conputer react to that sensors value. O2
> sensors are designed to by accurate within a certain standard deviation...in
> other words they are not perfect(nothing is perfect, not even the PCM's)...
I will not argue this point. You will have to learn the hard way...like I did.
> Less number of variables as your testing.... actually dyno testing would
> give you more credible, comparable results, because a dyno offers fewer
> variables than real world conditions, ideal for testing and comparison( you
> should know that one, Mr. Engineer). As far as the 5 dyno runs providing 5
> sets of data... you run 5 tests, and you get 5 sets of data.... both
> methods are accurate to a degree...but neither is perfect. As for testing
> and comparison of small changes, dyno testing would actually be more
> accurate... do the research on that one (it's just basic scientific
> theory)...
The original point that I was arguing was under "normal light throttle" or
"cruise" type conditions. Then came all these dyno comparisons (typical). Lets
stick to apples how 'bout it? Afterall, during a dyno run (WOT or heavy
throttle) the O2 sensors AREN'T EVEN BEING USED! <the nerve>
> >All closed-loop situtations (if functioning properly) will AVERAGE in the
> long
> >run to be almost exactly what they are trying to achieve. It's only been
> that
> >way for over 50 years. Do some reading on control circuits. I have a
> degree
> >from an accredited Engineering school in just that - do you?
>
> you say average.. we are looking at actuall readings, not averages... And
> yes, I do have a degree form an accredited engineering school.... :-)
>
> over 50 years? I didn't know that electronic (not mechanical) fuel
> injection has been around that long....
Which part of my post did I say that? You even posted it above. Can't you
read? And yes, closed-loop control has been around for way longer than 50
years. Nowhere did I even mention anything about a computer in that statement.
Again, lets stick w/apples to apples shall we? <wheres my moron crayons>
> So, if the PCMs are so accurate and functiuon SOOOO well (according to you),
> Why is it that so many Dakotas have catalytic convertors that go bad so
> soon? The number one cause of catalytic convertor failure is due to
> improper fuel mixture.... How about it Mr. Expert?
I've been intentially avoiding the cat issues (to try to keep the subject matter
focused) but if you must know - I've stated that in the archives before
(multiple times) also. Factory calibrations provide overly rich conditions
during open-loop control. This is done as a safety measure to account for
modifications, initial ambient pressure estimation errors, production line
tolerance variations, and many other reasons. Think about it - would you prefer
to err on the lean side?
You'll need to start showing some more intelligence or I will refuse to even
reply to your drivel.
Shane
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:03:52 EDT