1.5T Guide to DIY Flex Fuel Kit for Hondata or KTuner

slicksta637 said:

Here is my setup

Can hondata or so one chime in on why I get a 51 percent ethanol when I haven’t filled it with E85 yet. How do I calibrate the system using Hondata software

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You have an issue with your wiring. Be careful driving the car like that.

slicksta637 said:

Here is my setup
Can hondata or so one chime in on why I get a 51 percent ethanol when I haven’t filled it with E85 yet. How do I calibrate the system using Hondata software

Click to expand...

It's not a calibration problem. that's a wiring problem. Maybe you tapped into the incorrect wire or maybe a ground problem.

I wouldn't drive on the flex fuel tune until you figure out that wiring.

dc2turbo said:

For KTuner users, you will need to use the KTuner converter and not the other 2 listed.

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Why is this? Voltage differences or what?

Streetthrowback said:

Same here, I just finished installing the flex fuel kit on my fk8, on the flash pro guage it reads 15% ethanol and on the zeitronix it reads 10% ethanol, does anyone know why that is? kinda confused as to why they read differently

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If you are on straight pump gas with no added ehanol you should be reading at 9 to 10 percent. I would stick with the zeitronix.

boosted180sx said:

It's not a calibration problem. that's a wiring problem. Maybe you tapped into the incorrect wire or maybe a ground problem.

I wouldn't drive on the flex fuel tune until you figure out that wiring.

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Yes. he said it right. Wiring problem and tapping problem. I had this issue when i did mine on my Si. I did not have the proper fuse amps on the tapped for power and it read 51 like yours.

Can someone tell me what this flex fuel feature is mainly used for with Hondata?

chanman said:

Can someone tell me what this flex fuel feature is mainly used for with Hondata?

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More Power.

what is the purpose of the converter. cant hondata accept a 0-5v signal?

chanman said:

Can someone tell me what this flex fuel feature is mainly used for with Hondata?

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automatically adjust fueling and timing for ethanol content in your fuel. = more power

turbociv910 said:

what is the purpose of the converter. cant hondata accept a 0-5v signal?

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The sensor doesn't output a voltage signal the converter is what takes the signal which is a frequency with adjustable pulse width(how one signal can indicate content AND temperature) or something like that and creates both voltage signals but we're currently only using one for content

maddmatt02 said:

The sensor doesn't output a voltage signal the converter is what takes the signal which is a frequency with adjustable pulse width(how one signal can indicate content AND temperature) or something like that and creates both voltage signals but we're currently only using one for content

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got ya thanks, similar to CAN. Guess ive been lucky enough to just wire them straigth to aftermarket eucs all these years and never had to piggy back one onto a car. Dont have e85 around here either so pretty rare ..


here is gm part numbers with crimps..


GM Sensors


Below is a list of part numbers associated with the GM FCS (Fuel Composition Sensor) unit:

GM 12570260, Fuel Composition Sensor, Quantity 1

Delphi 12146121, Connector, Quantity 1

Delphi 12048074, Terminals, Quantity 3

Delphi 12052845, TPA, Quantity 1

Delphi 15324973, Cable Seal, Quantity 3

I'm easily overwhelmed by choices but determined to do the work myself. If someone has a specific parts list (links are a bonus) I can use, I'd pay a few dollars or be willing to send a bag of virgin crush washers in exchange.
I'm running ktuner and have a mishimoto catch can that requires the fuel line clip to remain as-is. The sooner I get it, the sooner everyone is a lot more likely to have a funny thread on a blown turbo or engine to read. Think on it.

I used to be more active on YouTube. Think I got a video or two from when I did mine myself and pretty sure I listed what I used. Caraddict is the channel name. If I think of it later I might reply back with the parts I used.

So if the converter just changes the signal of the GM ethanol sensor from freq to Vdc why aren't we using this thing?

https://www.amazon.com/KNACRO-Frequency-Voltage-Conversion-Converter/dp/B06XZFKZM4

I figure, fab the set up outside the car. Run some know non-ethanol gas through the sensor to get your zero value (the board can be calibrated) and then with some test strips, test your gas to get a know value of some E(x) gas and calibrate the span.

https://www.amazon.com/REV-X-Super-Tester-Flex-Ethanol/dp/B073HLSVHX/ref=sr_1_fkmr1_2?crid=202Z9H9V9O4QP&keywords=ethanol+test+strips&qid=1573668855&sprefix=ethanol+test,aps,134&sr=8-2-fkmr1

with the test strips and converter you'll pay less than $30 for a verified operational ECA.

@dc2turbo What was the purpose of going through the firewall?