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<DIV><FONT size=2>Instead of using mph, maybe just use the G-Tech to measure G's
between 4000-5500 rpm's in say 3rd gear. Look for Max G's on the same
section of road</FONT></DIV>
<DIV><FONT size=2>in the same direction. Raise Fuel Pressure do test
again, lower fuel pressure do test again. Go from there.</FONT></DIV>
<DIV><FONT size=2>Mark</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A href="mailto:wsherwin@home.com" title=wsherwin@home.com>Walter Sherwin</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A href="mailto:gmecm@diy-efi.org"
title=gmecm@diy-efi.org>gmecm@diy-efi.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, November 08, 2000 7:17
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Bad oxygen sensor ?</DIV>
<DIV><BR></DIV>
<DIV><FONT size=2>Wuuullll, I for one would be genuinely interested in
hearing what Bruce's answer was at the 3rd GEN list (yeee gads, I can hardly
find enough time for just 2 lists, how does he do
that?)..........</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2>However, Edmund, you mentioned in subsequent posts
that you backed fuel out via the VE tables and went from 98 to 104 MPH in the
quarter!? This seems a bit odd after having just added headers. At
first glance I would have suspected that your headers (and associated
exhaust system) had actually have forced you lean. But, this would
contradict your later findings. Someone else suggested checking fuel
pressure during the run (excellent idea), but, this would not play well with
reduce VE's either. The list of scenarios can go on, and on, and on, and
each can be methodically eliminated via real world testing, but, I want the
Reader's Digest version please........</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2>What cal and ECM are you running, and is it MAP or
MAF?</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2>Walt.</FONT></DIV>
<DIV> </DIV>
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<DIV> </DIV>
<DIV><FONT face=Arial size=2>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.</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>p.s. I know Bruce already answered this on the
thirdgen.org message board, but I wanted some more opinions
:)</FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>