MoTeC Global Forum

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.

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.

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.

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.

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

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.

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

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.

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.

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!