UPDATED!! OFT E85 EL map, high LT fuel trim

[zmz0305]

Data log update of 9/10/2016

This is the data log of my tank of 1 gallon gas + 8 gallon E85 mixture after 1/4 tank gas of drive.
http://www.datazap.me/u/zmz0305/log-...0&data=1-10-11

After this log I again added a full tank of E85 into my 1/4 tank remaining of mixture. I'll do a log for this tank later to see how it goes. Hopefully LTFT should rise to not too high and drops after ECU learns the trim. We will see.

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Second day update:

I added 1 gallon of gas to my half tank of E85. After some drive today, in the end my LT fuel trim dropped under 5% again. So I suspect it is the ethanol content that the E85 tune does not accustoms very well.
Hope this finding helps.

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Hi guys,

I have been running E85 in my car for three tanks now using E85 EL OTS tune from OFT.

The first tank, along with around 2 gallon 93 in it, runs fine. LT fuel trim is around 5% but not too high. The second tank, when idle LT fuel trim can be up to 9% and I am a bit nervous now. Now is my third tank, LT fuel trim is 17% when idle and it is scaring me. LT fuel trim will drop to 0~5% when giving it some or a lot gas, but still, is it normal?

I have a drop in filter, inlet tube and perrin exhaust. It runs perfect with stage1 93 tune.

Any enlightenment is very appreciated!

[phrosty]

Can you post a data log? LTFT tends to vary at idle due to raising IATs, but to go from 5% to 17% would seem to indicate something wrong.

[RacerX661]

Check for a exhaust leak around headers

[zmz0305]

Originally Posted by phrosty

Can you post a data log? LTFT tends to vary at idle due to raising IATs, but to go from 5% to 17% would seem to indicate something wrong.

See my update above.

I did a log today but everything seems fine now. The worst LTFT I get is 4.65 so I guess it's just the gas I need to worry about.

[DarkMatter]

Aw man lol. After filling up with e85 I noticed my LT trim goes from 14 to high 30's. Just a lot of fluctuation. I'm just going to assume it's bad gas and going to switch back to 93 after this tank is done.

[swarb]

Originally Posted by DarkMatter

Aw man lol. After filling up with e85 I noticed my LT trim goes from 14 to high 30's. Just a lot of fluctuation. I'm just going to assume it's bad gas and going to switch back to 93 after this tank is done.

If it's in the positive range, you can put a gallon or two of 93 to drop it down. As simple as that.
High 30's ltft is unusually high, which tune do you have? Or mods? You should double check if you have the right tune loaded and take some logs and ask someone to check them out.
Also an e85 tester is helpful if you are unsure about fuel quality.

[DarkMatter]

Originally Posted by swarb

If it's in the positive range, you can put a gallon or two of 93 to drop it down. As simple as that.
High 30's ltft is unusually high, which tune do you have? Or mods? You should double check if you have the right tune loaded and take some logs and ask someone to check them out.
Also an e85 tester is helpful if you are unsure about fuel quality.

This is my 4th tank so far? After flashing the first time around, I didnt bother to check my trims anymore.

I'm on OFT with stage 2 UEL e85.

I have rev works header, trd exhaust, front pipe, and takeda intake. I really dont know what's going on, but I'll check it more thoroughly tomorrow.

[swarb]

Originally Posted by DarkMatter

This is my 4th tank so far? After flashing the first time around, I didnt bother to check my trims anymore.

I'm on OFT with stage 2 UEL e85.

I have rev works header, trd exhaust, front pipe, and takeda intake. I really dont know what's going on, but I'll check it more thoroughly tomorrow.

You really need to do maf scaling for the intake. That is probably the problem.

[phrosty]

Originally Posted by DarkMatter

Aw man lol. After filling up with e85 I noticed my LT trim goes from 14 to high 30's. Just a lot of fluctuation. I'm just going to assume it's bad gas and going to switch back to 93 after this tank is done.

Are you 100% sure you're on an E85 tune? This is the behavior of a 93 tune running E85 gas.

[DarkMatter]

Originally Posted by swarb

You really need to do maf scaling for the intake. That is probably the problem.

IF this is the case, will switching back to the OEM intake resolve the issue?

Originally Posted by phrosty

Are you 100% sure you're on an E85 tune? This is the behavior of a 93 tune running E85 gas.

I'm sure...I downloaded the e85 tune from the new update. I even checked the tune on my car today and it said Stg2 UEL e85 A01C.bin

http://imgur.com/a/YCcMG

This is a quick log I did. Idk wtf is going on

[swarb]

Originally Posted by DarkMatter

IF this is the case, will switching back to the OEM intake resolve the issue?

If maf scaling is the issue(most likely), then yes. The only other thing is; there could be an exhaust leak. Or really high ethanol content, but very unlikely.

Intakes mess with maf scaling/fueling because they change the diameter of the inlet pipe for more air to lean out the fuel mixture and that is why they make more power. And that is why your ecu is trying to add fuel to compensate for the added air.

Good luck, please let us know if it works out.

[swarb]

I suggest you try to avoid driving hard with any where near 30% ltft. Try swapping the intake and see if it improves. If it does, you can run some logs and post in the log thread for some opinions. If all is good, you can try maf scaling on the aftermarket intake.

Look for posts by steve99 and check his signature for a bunch of links and info maf scaling, logging, and tuning in general.

[DarkMatter]

Originally Posted by swarb

If maf scaling is the issue(most likely), then yes. The only other thing is; there could be an exhaust leak. Or really high ethanol content, but very unlikely.

Intakes mess with maf scaling/fueling because they change the diameter of the inlet pipe for more air to lean out the fuel mixture and that is why they make more power. And that is why your ecu is trying to add fuel to compensate for the added air.

Good luck, please let us know if it works out.

Originally Posted by swarb

I suggest you try to avoid driving hard with any where near 30% ltft. Try swapping the intake and see if it improves. If it does, you can run some logs and post in the log thread for some opinions. If all is good, you can try maf scaling on the aftermarket intake.

Look for posts by steve99 and check his signature for a bunch of links and info maf scaling, logging, and tuning in general.

Ah, makes sense. I will replace the Takeda tomorrow with stock and reflash the e85 tune.

Hopefully it'll work out. Thanks for everything! Appreciate the help
I saw the threads. MAP scaling seems like a pain in the ass, but if the stock intake doesn't fix the issue, then I will go that route.

[swarb]

Originally Posted by DarkMatter

Ah, makes sense. I will replace the Takeda tomorrow with stock and reflash the e85 tune.

Hopefully it'll work out. Thanks for everything! Appreciate the help
I saw the threads. MAP scaling seems like a pain in the ass, but if the stock intake doesn't fix the issue, then I will go that route.

There is a thanks button on the bottom right of each post.

The tune is made for the stock intake.
If replacing the intake doesn't work, then it isn't the intake that is causing the problem. At that point I would say there is an exhaust leak at the header somewhere, or you have much bigger problems and I'm out of ideas. I'm pretty sure it's the intake.