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Flex fuel learn

FruityJudy

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Ran car to 0 miles to empty. Added about 12.5 gallons of E85 that was hand testing about E75. Idled for probably 15-20 min yesterday afternoon and was at 54% on alch percentage per nguage. Started car today and started driving softly. Have gotten to 63.5 on alch percentage but no higher. Currently at idle I am at 2-3 on Bank 1. STFT1 is reading about 2-3 numbers below STFT2 at all times. LTFT1 is reading 5 whilw LTFT2 is reading 2. Also Nguage AFR1 and AFR2 are reading 14.5-14.7. Lambda .99 to 1.00 on both banks also but car dash air fuel is reading 10.9.
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fuelforfire87

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At zero miles to empty there is still a gallon or so of gas left in the tank. So when your flex fuel tune is learning the alcohol percentage it will be a little less than 75%. According to this fuel mixture website you should effectively have E70.

http://www.wallaceracing.com/ethanol-mix-calc.php

Flex fuel tunes use the wideband o2 sensors to learn the alcohol percentage and are not as accurate as using a true flex fuel sensor, so your learned alcohol percentage can be more or less than what you actually tested it at.
 
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FruityJudy

FruityJudy

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At zero miles to empty there is still a gallon or so of gas left in the tank. So when your flex fuel tune is learning the alcohol percentage it will be a little less than 75%. According to this fuel mixture website you should effectively have E70.

http://www.wallaceracing.com/ethanol-mix-calc.php

Flex fuel tunes use the wideband o2 sensors to learn the alcohol percentage and are not as accurate as using a true flex fuel sensor, so your learned alcohol percentage can be more or less than what you actually tested it at.
Im fine with the ethanol being what it is, my concern is why is my nguage reading a different afr than the car.
 

fuelforfire87

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Im fine with the ethanol being what it is, my concern is why is my nguage reading a different afr than the car.
The ngauge AFR readings are for pump gas only. meaning they won't adjust for ethanol blends. As long as your lambda is close to 1 which you say it is, you are fine.
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