O2 sensor oscillations

[mrvette]

Soyou are running an engine?   I kinda thought you were just doing an electronic
mock up,....GENE

Bruce Plecan wrote:
> 
> -----Original Message-----
> From: mrvette <mrvette at bellsouth.net>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Friday, October 23, 1998 2:21 AM
> Subject: Re: O2 sensor oscillations
> 
> >Bruce, from reading the below, it sounds as if you are running one on a
> bench,
> >not an operational engine, is this correct?
> 
> Right
> 
>   if it is, than your comments seems
> >to make sense, as that is what would happen on a bench...as a dynamic
> running
> >system on an engine, there would have to be something wrong,
> 
> What's the something?.  By using one injector to trigger the O2,
> that's the same as the exhaust pulsations off of a 2 barrel TBI,
> on a dual plane.  The 55 trims the pulse lenght, and I clip the O2
> v.  So what's missing?>
> Bruce
> 
>  ....GENE
> >
> >Bruce Plecan wrote:
> >>
> >> -----Original Message-----
> >> From: Greg Hermann <bearbvd at sni.net>
> >> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> >> Date: Thursday, October 22, 1998 9:46 AM
> >> Subject: Re: O2 sensor oscillations
> >>
> >> >>OK, Here's a question:
> >> >> I read that, while in closed loop - the voltage on the O2 sensor is
> >> >>supposed to cross 0.45 at some particular rate.
> >> >>
> >> >> Are these crossings producted by "puffs" of exhaust going across, or
> is
> >> >>the ECU intentionally running lean-rich-lean-rich-lean in order to keep
> >> >>the avg mix (over time) "centered" on the ideal?
> >> >>Thanks!
> >> >>-Bill
> >> >>I dunno, but some time with a scope hooked up to look at the frequency
> of
> >> >>the crossovers vs ignition spark frequency might well begin to give an
> >> >>answer--anybody???
> >> >Regards, Greg
> >> >
> >> Running car-no.  Final info.-no.  As things look, right now, on the
> >> bench the ecm looks for a +v at a particular time, in ref to a ignition
> >> event, as seen by the O2.  TBI, much less picky then TPI.
> >>   This O2 feedback to ecm is a pain.  +v is a function of inj PW,
> >> and a time delay, from when Int changed.  Maybe the duration of v+
> >> will work, but it's a guess for now.
> >>   With the 747 I used a 555 on after delay and read off an inj fire
> >> signal.  Would kinda go closed loop properly but after time would
> >> go open, and wierd IAC BL INT numbers.
> >> Bruce
> >
> >--
> >
> >
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-- 


                                ____________
Fun under the sun in          //~~~~~~~~~~~~\\
Jacksonville, Fl.  :-)))     //______________\\
                       /~~~---~   |      |   ~---~~~\
                      /|    /______\____/______\    |\
                    (( | /      |          |      \ | ))   
     Mako 'Vettes    | \============================/ |   
 Shift better with   |\ \\[  ]    |mrvette|   [  ]// /|
     Automatics      | \/+========================+\/ |
                     |~==============================~|
                     |_____|                    |_____|
-------------------------------------------------------------------