Flex fuel sensor reading high
 

I have finally installed my flex fuel sensor on my 9093 mspnp g2.
In the settings I have 50hz at the min and 150hz as the high. It's is a continental unit (GM)same pn# as the haltech unit.

I have 93 Kentucky gas in it which I assume has at most 10% ethanol, however in tuner studio it is reading 30%!!
If I change around the min frequeny in the tuner studio settings I can get it to read, e10 but then when I added 3~ gallons of e85 to top of the 12~ gallon tank it was showing e50 anyone else have experience with ms and flex fuel sensors.

No personal experience, but I'm definitely interested to learn more.

My method would be to fill with E10, set low end reading so it reads 10%. Run the tank empty. Fill with E85, set the low end reading so it reads 85%. Ideally I'm sure you would want to test the gas going in the car, but I feel like that would get you a datapoint at each end of the scale so you could reliably interpolate between the two.

Don't do this. E85 is rarely true e85, more often that not it can be as low as e70. You need to get a baseline measurement and figure out what's going on. You may have a defective sensor. Try to find a station around you with ethanol free gas.

Unless you're mixing the E10 and E85 blends yourself, you have no earthly idea what the actual compositions are. Do not do this.

x1million

There is a possibility that the sensor is dead or perhaps there is a little water in my tank. that can cause havock with these sensors.
Need to empty the tank and run strate e0 93 then attempt again.
Any one had any experience with ms and flex fuel sensors reading high?

Not much of this exists. Yank is running one with success. I have one on my shelf.

Like I said, no personal experience, and I'm interested to learn more. I'll try to be more careful with my assumptions, certainly not intending to harm anyone's car. I'd love to see more Flex Fuel info on the site and hope this leads toward a constructive conversation.

If you have a safe tune on what comes out of the pump labeled as "E85" and reads 85% ethanol on your sensor, and a safe tune on what comes out of the pump labeled "E10" and reads 10% ethanol on your sensor, then I assumed a linear blending of those two tunes would result in a safe tune. The fact that those ethanol percentages may be off slightly doesn't seem like it would matter. If that's incorrect I'd love to understand why.

If you can't calibrate a sensor based on available information, what is the solution? I know you said find no-ethanol gas, but then what? Are these sensors just supposed to be 100% calibrated and you shouldn't adjust them?

Hmm I wounder if there is something similar to calibration tables for Afr sensors and ait sensors. that can adjust the calibration of the flex fuel readings within tuner studio.

Because as I said before. A pump labeled E85, DOES NOT MEAN 85% ETHANOL. Some places it can be as low as e70. And this makes a big difference. Sometimes it can be 85%, sometimes 70%.

The sensors read 50hz at 0% ethanol. and 150hz at 100% ethanol. Its different than a variable voltage sensor, for which the ADC sometimes needs to be calibrated. OEMs trust them from the factory, I assume we should too. Which is why I suggested a dead sensor, and that he should test it with e0, because that should give 50hz. If you can scope it that would be even better.

Calibration is 50hz=0% ethanol. 150hz=100% ethanol.

I assumed there would be since there is with everything else. If not, then that answers my questions.

You can calibrate if if you have a well known value. Which is why I suggested getting some e0. Getting e100 might be hard.

Irrelevant. E100 means 100% ethanol 0% gasoline. Not 100% pure ethanol.

How can 100% ethanol not be 100% ethanol? 100 percent meaning allofit.

I don't know if you just can't comprehend what I wrote or if you just didn't read it, but either way it makes trying to have a conversation totally pointless.

Do you read your post linked? It talked about distilling ethanol.

E85 does not mean 85% pure ethanol. It means 85% is ethanol that is distilled to be as pure as possible. E100 means no gasoline added to that. You guys are slow as shit this morning.

Because for like the 3rd time what comes out of the pump is not always e85. And varying percentages can mean anything from low on power to destroying your engine.

Let's say you set up your sensor so e75 reads as 85% ethanol, and e10 reads as 10%. Your whole blend is screwed up. What if you then mix in some e83. Now you are over your calibrated "85%" ethanol. Something you might not have tuned for

^So you meant that?^

No, quit being fucking pedantic, it probably has all sorts of shit in it. But the designation e85 is the percentage of "ethanol" (percentage of actual pure ethanol i have no idea) compared to the percentage of gasoline. I'm not trying to argue about the contents of ethanol, shit, i don't even care. I'm trying to explain to you what it means in terms of ethanol blended fuel. And I'm about to give up.

I know what you mean, I'm just busting your balls. E100 isn't 100% ethanol.

Its 100% not gasoline. Which is all I care about.

It is 100% of ALLOFIT!!!!

:fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk: :fawk:

Now we're talking! :party:

I might install a flex fuel one day, we'll see. The big problem for me is I can't run on pure gasoline at 28 PSI without detonation, and the amount of timing I have to pull to keep it from detonating is unacceptable from an EGT standpoint. So all I could really use it for is to compensate for different E85 blends, but so far in TX, I haven't noticed any change so far. E70 is the minimum here, so maybe it's not enough difference to notice.

coldside wastegate with EBC. Blend boost by ethanol percentage.

Sounds dumb, but probably the only legit way to actually make it driveable in boost on pump gas. So I guess, not dumb? :idea:

I wasn't really kidding. Ive seen emilio mention it before, and seen it done in a few random places online. And its actually quite simple, and mechanical.

Funny part is the "hardware" to do this is already on the car and being used as a bypass valve to cool the SC when not in boost.

But I'll probably never do this, just keep it on E85.

For some reason the wastegate is supposed to be as close to the intake as possible. Even on the actual intake mani if possible.

Subbed for more info. I just installed one of these also.
I bought this tester:
One Tester to Check Your E85 and Gasoline Fuel for Ethanol Levels | eBay
You guys probably have seen this stuff already, but here it is anyway.
Megasquirt Support Forum (MSEXTRA) ? Set up Continental Flex Fuel Sensor 13577394 (View topic)
and
Flex Fuel with MegaSquirt

Don't use the megamanual. It's not for the msextra codebase.

My bad, as usual I know just enough to be dangerous.

Other link is good :bigtu:

I have another flex fuel thread with links to Miata maps with flex blending.

I don't have a flex fuel gauge yet and I'm about to dyno tune my car. I got a fuel sample test kit to know how much ethanol my "e85" has. If it's low on ethanol, let's say 75% and I tune for that, my understanding is that it will be safer in the summer when I get true e85. Yes, I may not extract it's full potential but it should be safe, right?

Thread from the dead, but potentially relevant

I installed the Continental long tube sensor part number 13577394 and also had readings of ~35% on E10. I bumped around the google, and it sounds like several people have gotten very similar readings from this sensor out of the box. We have measured ~75Hz with air, ~85Hz on what may be E10 pump gas, and around 150Hz on whatever blend our e85 actually is. I took it a step further and ran water through it, 190Hz.

It seems getting one that provides the typical 50-150Hz range is a bit hit and miss. I will be putting some E0 through this one sometime here soon, as well as possibly some 70% ethanol water.

I will also be ordering another sensor. This one was sold as new Continental Branded, but it came from China, so I bet it is counterfeit.

Solved
 

Thanks guys for all your input i replaced my flex fuel sensor with another one and it reads correctly. enjoying my summer with a bit of corn