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Old 08-14-2009, 12:14 PM   #1
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Default bucking when letting off throttle ever so slightly

If started tuning the fuel table today and found that when I'm letting off the throttle ever so slightly, I get (violent) bucking. It's clearly visible in this log.
When I let off the throttle abrupt, everything is fine (first pull), but when I let off ever so slightly (consequent runs), the car starts bucking. The 3-4 spikes are very apparent. Same thing when I step on the throttle again (but less hard)
This was done at full throttle, but I have the same behaviour at partial throttle. Only on light throttle (cruising with the flow of traffic), I don't get this behaviour.
How can I best solve this?

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Old 08-14-2009, 12:37 PM   #2
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he opens acceleration wizard and fools around.
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Old 08-14-2009, 12:51 PM   #3
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Old 08-14-2009, 01:31 PM   #4
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I have acceleration turned off, like the tuning manual suggests (while tuning), so the bucking when acceleration is probably normal, but does accel fuel also have an impact when letting go of the throttle?
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Old 08-14-2009, 01:32 PM   #5
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This video is not available in your country due to copyright restrictions
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Old 08-14-2009, 01:49 PM   #6
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post your over-run window. What's up with that random off-throttle PW jump?
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Old 08-14-2009, 04:02 PM   #7
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over run is turned off. I tried with it turned on, but get the same results.
When turned on, I'm using:
>1500 rpm
>22kpa
<5 tps
>32C
1.5 s (going to increase a bit to prevent going lean in between lazy shifts)
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Old 08-14-2009, 04:45 PM   #8
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It's the lack of decel and accel. Ignore this for now and try driving smoothly to tune the basic VE table. once AE is enabled, you will take care of the jerking.
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Old 08-14-2009, 05:18 PM   #9
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or just tune the enrichments on a usable map, then fine-tune with them activated.
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