PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

PE tuning ? spikes

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Old May 26, 2005 | 05:38 PM
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Default PE tuning ? spikes

I am tuning my WOT PE table on the street with the help of LM wide band.
I have it tuned straight line between 13.02 to 13.06 except for two spikes down around 12.6.
The 1st one start to spike rich right after 4800 to 12.6 then back to 13.05 by 5200.
The 2nd one start to spikes rich right after 6400 to 12.6 then back to 13.06 by 6800.
The 1st spike is at max TQ and the second spike is at max HP. There is no PE cell at the spike points. Both spikes are in between cells and both cells prior and after are around 13.0?. I tried leaning the cell prior and after with no luck.
Does anyone have any info on how to tune out the spike?
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Old May 26, 2005 | 06:44 PM
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Did your timing change due to a knock event during those periods?
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Old May 26, 2005 | 07:03 PM
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Unless you have knock/miss, you'll have to do the best you can with the resolution available.
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Old May 26, 2005 | 07:27 PM
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can you post your tune, or pe table?

Ryan
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Old May 27, 2005 | 09:20 AM
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There is no Knock and no positive Ltrims carrying over.
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Old May 27, 2005 | 09:25 AM
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what does your commanded airfuel ratio do at those points?

Ryan
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Old May 28, 2005 | 12:14 AM
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Here is a copy of my PE vs RPM table.
My Wide band 02's are right at 13.02 to 13.06, straight as a arrow except at 4900 and 6500RPM'
What is the commanded airfuel ratio?

1.2035 1.2035 1.2035 1.2035 1.2035 1.2035 1.2035 1.2035 1.2035 1.2016 1.1812 1.1928 1.2248 1.1948 1.2054 1.2190 1.2141 1.2074 1.2112
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Old May 28, 2005 | 04:57 AM
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commanded airfuel ratio isjust that, what airfuel ratio the pcm is trying to achieve. Do a log with it selected, and you will see how far off your tune is. Based on your PE table, and the air fuel your shooting for, you need to make changes in other places than the pe table imho.

Ryan
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Old May 28, 2005 | 11:34 AM
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Slow,
I have Edit and Auto Tap, how can I see the commanded airfuel?
Where are the other place I need to make changes to?
Thanks for your input and help.
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Old May 28, 2005 | 12:08 PM
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auto taqp should allow you to log commanded airfuel ratio. but I have never tried with that software. Hopefully somebody can post up and tell you how to log it.

Once you log it, compare that to the airfuel your seeing. If they don't match, you need to determine why they don't match. most likely wrong airflow information, but if you've changed injectors, or your fuel rail is not staying at 58 psi, it could be fueling issues too.

Ryan
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Old May 29, 2005 | 07:38 AM
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Can anyone tell me if Auto Tap can log Commanded Air Fuel like slow has suggested?
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Old May 29, 2005 | 10:18 PM
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it might have something to do with COT (cat over temp) settings . Have you got this disabled?
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