Bad oxygen sensor ?

[Bruce Plecan]

MPH
G-Tech is one such tuning tool.
In car DIY timer off of VSS will do for the EE crowd

WB, and EGT tell you about where you are AFR,
Performance measurements dictate what the engine wants
Bruce


> So what do you tune by if not the o2 sensor ? SOTP ? 1/4 mile times ? MPH
at
> the end of the quarter ?
>
> ----- Original Message -----
> From: <timsiford at hushmail.com>
> To: <gmecm at diy-efi.org>
> Sent: Wednesday, November 08, 2000 10:50 AM
> Subject: Re: Bad oxygen sensor ?
>
>
> > First the standard O2 disclaimer....
> >
> > Tuning by O2 voltages can be highly inaccurate.
> >
> > With that said ... I would check two things...
> > 1) Tape a Fuel Pressure guage to your windshield and have a buddy sit in
> > the passenger seat as you do a WOT run.  Have him watch the FP guage
> ESPECIALLY
> > in 3rd gear to see if your FP is decreasing.
> > 2) Check your header collectors.  In some cases high speeds can act to
> force
> > fresh air into the collectors if they are not tight.  The extra O2 will
> > register on the O2 sensor.
> >
> > Tim
> >
> > At Wed, 8 Nov 2000 09:59:08 -0800, "Edmond" <euro at lvcm.com> wrote:
> >
> > >
> > >
> > >I did several 1/4 mile runs after I installed my Edelbrock headers and
> > >=
> > >brand new o2 sensor. First and second gear are nice smooth 900mV range
> > >=
> > >ramps. Once it hits third gear is starts descending rapidly to about
> > >=
> > >400mV and stays down until I let off the throtle. I wish I was at home
> > >=
> > >so I can show you the exact Diacom graph. I tried giving it more fuel
> > >=
> > >(almost 95 in the VE tables) between 90-100 KPA but it still does this.
> > >=
> > >The engine runs fairly well at WOT, but I cant really tune it w/out
> > >=
> > >gettting some accurate info from the sensor. My old 80K mile o2 sensor
> > >=
> > >in the exhaust manifolds didnt do this at all. Could this indicate a
> > >bad =
> > >sensor ? I should mention at idle it goes from 40-50 to 800-900 almost
> > >=
> > >every 1/2 second. It does this at light cruise too. Maybe it's time
> > >for =
> > >a heated sensor ? Still downt explain the WOT weirdness though since
> > >it =
> > >should be nice and hot.
> > >
> > >
> > >
> > >p.s. I know Bruce already answered this on the thirdgen.org message
> > >=
> > >board, but I wanted some more opinions :)
> > >
> > >
>
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