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Thread: o2 readings and timing

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  1. #1
    Join Date
    Apr 2003
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    Allen, Tx(DFW)
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    Finally got my ltrims locked in at 0 at wot. However my o2 readings are .945-.975 at wot. How much fuel do I need to pull in order to get this down to .900 or so?
    Also, what tables in high octane start wot? thx
    02 Silverado
    02 TrailBlazer

  2. #2
    Join Date
    Jun 2003
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    713
    cool mine will actually go to 1015 every once in a while. this is a good thing. just means they are doing there job.
    04 supercrew 5.4 3 valve-magnaflow catback



    formerly 02denali 12.79@107

  3. #3
    Join Date
    Mar 2003
    Posts
    250
    You can start pulling fuel out 1% at a time and then scan it. It's better to get your AF tuned with a wideband. If you have a scanner, log a run at WOT. Look at the timing at a certain RPM then look for that number in your HOtable. With my scanner it is very easy to graph timing and RPM's together. Add timing until you get a little knock then back it out. That is the way that I do it, and it has worked so far. I am running 30* with no knock.
    2002 ecsb
    LS1
    JPR stage I heads
    218/224 529/536
    AS&M Headers
    Volant, Magnaflow Dual/Dual
    SSF 3500 4.10

  4. #4
    Join Date
    Nov 2003
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    52
    Normal O2 switching occurs between 200 and 800 millivolts, with 450mv being the switch point. During normal running conditions, is is not unusual to see voltage as low as 100 mv and as high as 900mv. During WOT, voltage should immediately go to AT LEAST 900mv, and may reach 1 volt or a little higher. Going over about 1.2v can sometimes cause problems, as there might not be a strategy for voltage that high, so the computer reasons that since voltage is not between 450 and 1.2 millivolts, the system must not be rich, so it has to be lean. That can cause all sorts of problems!



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    Jason B. Armstrong, L1, AAM
    http://www.danasoft.com/vipersig.jpg

  5. #5
    Join Date
    Mar 2003
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    That's a little high at wot. .900 seems to be a safe number, shoot for 870-890.
    If you have cot enabled, you'll have a tuff time tuning for wot a/f ratio.

    later,

    allen

  6. #6
    Join Date
    Apr 2003
    Location
    Allen, Tx(DFW)
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    445
    Originally posted by farmtruc@Jan 15 2004, 09:16 PM
    That's a little high at wot. .900 seems to be a safe number, shoot for 870-890.
    If you have cot enabled, you'll have a tuff time tuning for wot a/f ratio.

    later,

    allen
    What does disabling COT do? Can I do that without any other changes? Its currently set at true.
    02 Silverado
    02 TrailBlazer

  7. #7
    Join Date
    Apr 2003
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    Allen, Tx(DFW)
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    Used the ole search feature and found the answer I was looking for. thx
    02 Silverado
    02 TrailBlazer

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