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Old 03-27-2006, 03:31 PM   #1
Jeramie
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Default Air Fuel Learning (Long Term Fuel Trim?)

Over the past few months I have been tunning my car using the Openecu tools. After flashing a new tune everything goes just fine and then after a few days the car starts pulling timming. It was suggest by someone that I take a look at the Air/Fuel learning, which from what I understand should be -/+ 5%, anything more requires attention (Correct me if I'm miss informed). My vaules range up to +7%.

I suppose my question is, does this require attention and if it does, where should I look for a problem. I've search, and I really can't find much related to Air/Fuel Learning or Long Term Fuel Trim. At this point I'm rdy to rip my hair out, everytime the car is running good (or great), it only takes a few days for it to be ruined. Any ideas about how to track down this problem would be a great help. Thanks

04 WRX
Uppipe
Downpipe

Stock image (with OL/CL fixes). If any other info is needed, logs ect, let me know and they can easily be provided.
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Old 03-27-2006, 04:11 PM   #2
R4ND0M_AX3
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Is it bad at all loads/rpms or just specific areas?
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Old 03-27-2006, 04:15 PM   #3
Jeramie
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Not quite sure what you mean? Is it pulling timming bad at certian spots/load points or is the Fuel trim bad at certian load points?
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Old 03-27-2006, 04:29 PM   #4
hotrod
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what is your knock correction?
Sounds like the ECU doesn't like your tuning choices and is trying to save the motor.

Larry
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Old 03-27-2006, 04:34 PM   #5
Jeramie
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Quote:
Originally Posted by hotrod
what is your knock correction?
Sounds like the ECU doesn't like your tuning choices and is trying to save the motor.

Larry
I would normally agree with you, but this is not my tunning now it SOA's tunning.

KC values range from 6 - 12 under WOT.
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Old 03-27-2006, 04:39 PM   #6
Jeramie
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http://www.computercablestore.com/log.csv

Thought this would make it easier, sorry about the size of the log. It was my drive home for lunch today (which I was looking for A/F learning). There are a WOT (not the best but should give you the idea).
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Old 03-27-2006, 06:14 PM   #7
Jon [in CT]
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The data in the column labelled "Air/Fuel Correction #1 (%)" have an interesting range, from -25 to +25. I doubt that's valid.
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Old 03-27-2006, 07:15 PM   #8
cdvma
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Quote:
Originally Posted by Jon [in CT]
The data in the column labelled "Air/Fuel Correction #1 (%)" have an interesting range, from -25 to +25. I doubt that's valid.
Without looking at the log thats a perfectly valid range. Once it settles on a value it sets that into the long-term fuel trims and starts over at 0 again.
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Old 03-27-2006, 10:42 PM   #9
nhluhr
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You would not see that value with a stock airbox and a properly functioning car.

Those are the MAX values for that parameter. It can't correct anymore than that.

edit - nevermind i was thinking you were talking about the Learning values.

And having taken a look at the learning values, they are PERFECTLY normal for a stock airbox.
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Old 03-28-2006, 08:34 AM   #10
Jeramie
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Quote:
Originally Posted by nhluhr
And having taken a look at the learning values, they are PERFECTLY normal for a stock airbox.
Thats what I like to hear. Thanks for taking a look guys.
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