Flex Fuel sensor issue

[JordonMusser]

Everything seems to be functioning as it should with my flex fuel system, although the Eth content doesn't seem to change. Ive been running e85 from the pump for about a year, and it has never flucuated more than .5% from 85-86%. Clearly there is no way, as this is just pump fuel.

When i first installed the sensor I ran 93 then switched to e85, and the sensor responded correctly. No diagnostic issues, fuel temp looks roughly correct. For ref, this is the sensor I am using: https://www.atpturbo.com/mm5/merchant.m ... gory_Code=

I believe eth% is communicated via changing frequency, the raw voltage (shown at bottom of the attachment) does fluctuate as expected, but I have not logged.

Any thoughts? Clearly it could be a bad sensor, but just making sure I am not missing anything obvious.

[SteveC]

I actually unknown to me purchased a fake sensor - and this worked at the start then just read E60 all the time.

New sensor direct from Motec fixed this but there seems to be a lot of bogus parts available at the moment.

[Stephen Dean]

Try changing the calibration to Manual and use 50 = 0% and 150 = 100% for the table.

Some of the sensors that are labelled as being Continental do not work the same way.

[JordonMusser]

Stephen,
I gave that a shot (50hz to 150hz I assume) but no dice. voltage ref from Hybrid A is at ~.141

So my assumption is bad sensor. but open to more ideas.

[JordonMusser]

If it makes a difference, I am using 13577394 (long arm)

[Stephen Dean]

I have one of the long arm sensors in my car and I use the above calibration for it.

Water in the fuel can also cause higher numbers.

[JordonMusser]

Ya definitely not water. I ordered a new sensor will see how that shakes out since it appears I have it setup correctly.

Thanks for the input

[JordonMusser]

Following up. Replaced sensor and still getting the exact same 85%. This sensor was brand new in a AC DELCO bag, so I have to assume its correct. Its the "long style".

Any help on further diagnostic? No way is my local Kroger 85% all the time my old car with a proEFI setup said it was 65-80 typically.

[MalcolmG]

why don't you dilute it 50% with petrol and see whether it comes down to 42% It sounds like you're diagnosing a faulty sensor due to a hunch, despite 2 sensors giving you the same reading.

[JordonMusser]

Welp, i am a fucking idiot. The sensor did respond when I added a few gallons of 93. I am going to get an eth tester and compare it to fuel in my system and see how well it correlates to my sensor reading.

Guess I am lucky I am getting good % eth!