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Re: Bad oxygen sensor ?
It sounds like a plugged fuel filter, fuel pump starting to go bad, or
plugged fuel sock. The drop at WOT is indicative of leaning out... You
need to get a fuel pressure guage on the system and clip it under the
windshield wiper blade and see what FP does at WOT... My suspicion is it
will slowly drop as the O2 volts do... I suspect the old O2 sensor may not
have been reacting properly.
Just to make sure, run a wire from the engine block (ground) to the O2
sensor shell (use a hose clamp to hold it) and try again... Could also be
the headers not having a good ground.
At 12:59 PM 11/08/2000, you 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 :)
===========================================================
David Cooley N5XMT Internet: N5XMT@triad.rr.com
Packet: N5XMT@KQ4LO.#INT.NC.USA.NA T.A.P.R. Member #7068
I am Pentium of Borg... Division is Futile!
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