Flex Fuel Not Learning

[that_na_coupe]

Has anybody encountered this issue?

It seems to happens randomly on random vehicles, I mostly work with 2018+ Mustangs and F150s.

Most recently an Edlebrock F150 randomly stopped learning ethanol over 9.8%.
The only change between last and second to last revisions was the idle speed, and the truck stopped reading ethanol % over 9.8%

We loaded the last revision, where it did read the proper %, and it is still reading 9.8%


On other cars/trucks, with flex fuel enabled, the car/truck will not pick up the alcohol/ethanol % PID
I could put the identical tune from a car/truck that did pick up the PID and it still will not read it.

Any help is appreciated!

[mJolnir]

It happened to me on a 18 gt, at the end had to make a separate tune for e85, the car never learned any alcohol

[paulsmithsr]

Same her flex doesn’t work. After fills up

[that_na_coupe]

This is something I've tried, again it seems kind of random.

Some vehicles will take it with the e85 stoich and the trims will be in line. Others will still trim 25-30% as is it still had 14.07 stoich commanded.

[aaronson]

This is something I've tried, again it seems kind of random.

Some vehicles will take it with the e85 stoich and the trims will be in line. Others will still trim 25-30% as is it still had 14.07 stoich commanded.

How did you set up your inferred stoich percentages, I just tuned a 2020 and found that populating different values ie 14.08-10% 11.5-65% didn?t work but keeping it exactly as an f150 made it read properly

[b00sty]

im also having the same problem on a 2018 was runing perfectly for months then one day on half a fill of e85 it seemed not to relearn , so just in case i through another tank of e85 & it wanted to run as if it had 93 ?

[LastPlace]

Are you guys "writing entire" or flash "calibration" only?

[b00sty]

yes calibration only

but insaying that I just redone all of my flex tables & back on to 93, car starts idles & cruises better also my afr on the display seems more consistant 14.0 going to use as much as i can then start to add e85 see what happens.

[LastPlace]

It is widely known that flashing cal only will cause issues randomly.

write entire is your friend

[b00sty]

will do

[LastPlace]

Calibration only should be used when you’re in a time crunch on the Dyno.

Write entire for everything else

[aaronson]

Calibration only should be used when you’re in a time crunch on the Dyno.

Write entire for everything else

Interesting...I was always under the impression you?d only use write entire the first time, then write calibration thereafter or it would cause harm to
Your ecu. I always wondered about that because I feel like hand held devices like the SCT x4 and ngauge use the write entire method. I also noticed that when making changes to the trans aspect I wouldn?t notice a difference until I did the write entire. So would it be a safe assumption that write entire actually won?t hurt the ecu?

[LastPlace]

Interesting...I was always under the impression you?d only use write entire the first time, then write calibration thereafter or it would cause harm to
Your ecu. I always wondered about that because I feel like hand held devices like the SCT x4 and ngauge use the write entire method. I also noticed that when making changes to the trans aspect I wouldn?t notice a difference until I did the write entire. So would it be a safe assumption that write entire actually won?t hurt the ecu?

You are correct about sct and ngauge writing entire each flash.

So that should answer your question about it being "safe"

[that_na_coupe]

I did try doing a write entire, it didn't seem to be the solution to this issue.
On every vehicle that this has happened to I tried a write entire as well.

The only time I've seen the issue go away was on ANOTHER Edelbrock truck.
But no tune changes were made. It seems like it randomly went away after a flash.

I always use the F150 Flex Fuel tables and 99/100 times it works, but randomly I'll get a Mustang/F150 behave like we're describing. I'll end up flashing the car/truck countless times with no luck, and I end up having to send the customer off with a 91/93 tune.

I'd like to pinpoint this issue.

[aaronson]

I did try doing a write entire, it didn't seem to be the solution to this issue.
On every vehicle that this has happened to I tried a write entire as well.

The only time I've seen the issue go away was on ANOTHER Edelbrock truck.
But no tune changes were made. It seems like it randomly went away after a flash.

I always use the F150 Flex Fuel tables and 99/100 times it works, but randomly I'll get a Mustang/F150 behave like we're describing. I'll end up flashing the car/truck countless times with no luck, and I end up having to send the customer off with a 91/93 tune.

I'd like to pinpoint this issue.

It might lie in the specific ecu strategy that may have a bug. Try doing an info log and email support about it and see if maybe there?s a patch that?s applicable

[LastPlace]

Agreed there also might be a bug in whatever version of HP tuners you’re using and sometimes your strategy can get corrupted.

[aaronson]

Agreed there also might be a bug in whatever version of HP tuners you’re using and sometimes your strategy can get corrupted.

I actually had that happen to me on my personal car, it wouldn?t let me change specific base fuel tables to iron out cold starts on e85.

[that_na_coupe]

I emailed support, I'll update here if they give me an answer.

[OzTuning]

Write Entire, then Reset KAM after loading. Should work.

[that_na_coupe]

Write Entire, then Reset KAM after loading. Should work.

I did try this a few times before, I gave it another shot just to say I did.

Still nothing.

Support said everything was fine on their end and to look to the forum for advise