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Anyone get an occasional rough idle when the car is hot and on e85?

bootlegger

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Nah. 15-17 cars don't need a fuel system upgrade. Tune and gtg.
I thought they needed bigger injectors. Maybe I was just falling for vendor marketing here.
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Bluemustang

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I thought they needed bigger injectors. Maybe I was just falling for vendor marketing here.
Only for 18/GT350/CJ manifolds. You can do them on a stock car just to keep the duty cycle in a better place but it is not needed.
 

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Everyone in this thread has the car tuned specifically to run E85. Flex fuel cars have tunes to be able to adjust for 0-85% EtOH. The 2018 can run E85 with a simple tune, while 2015-2017 cars need a fuel system upgrade.
Thanks.. Is there a benefit from running that fuel? From what I research besides being somewhat more environmentally friendly there is no real hp or mpg gains..

https://www.fueleconomy.gov/feg/ethanol.shtml
 

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Thanks.. Is there a benefit from running that fuel? From what I research besides being somewhat more environmentally friendly there is no real hp or mpg gains..

https://www.fueleconomy.gov/feg/ethanol.shtml
Yep definite benefits. E85's octane rating makes it virtually knock proof, preventing your ECU from pulling timing. In addition, E85 cools the intake charge vs. traditional gasoline which improves volumetric efficiency.

You can expect 10-15 increase in peak hp/tq and potentially more gains down low due to the high octane rating allowing a more aggressive timing curve down in low and in midrange.
 

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Nuked

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I don't want to be that guy but now that the Gen 3 DI has been in the wild for a couple of years folks should keep an eye on AFR's especially if jumping lean on occasion. E85 is known to wreck havoc on HPFP's and no one really knows how robust this pump is yet. Running a tank of 93 every month or so probably isn't a bad idea.
 

Bluemustang

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My a/f hit 8.6 today @ idle. Lol. Can we say phat!
Something definitely sounds off. Seems to be running rich and sounds like your idle is inconsistent also.

To piggyback on what @Nuked just said - this is why I run a flex tune. It's easy to toss in some good ol' 93 every now and then, which is a good thing. I wouldn't run E85 exclusively.
 

Zelek

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I grabbed a couple bottles of Lucas ethanol stabilizer just to run through a few tanks of E85. I still run a tank of 93 here and there.
 

Zinc03svt

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I grabbed a couple bottles of Lucas ethanol stabilizer just to run through a few tanks of E85. I still run a tank of 93 here and there.
I have been running that since late last October. Every 2-3 tanks. Initially I was beginning to wonder if that product (Ethanol Safe) might be causing my problems...? The idle went to shit after last fill up though.
 

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E85 doesn't have the additives that quality 93 octane has. Something to keep in mind.
 

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Zelek

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I have been running that since late last October. Every 2-3 tanks. Initially I was beginning to wonder if that product (Ethanol Safe) might be causing my problems...? The idle went to shit after last fill up though.
I think you might have gotten a bad mix this round. That's the only explanation for it to do that all of the sudden. 3oz of the Lucas stabilizer should not affect 15 gallons of E85 in that manner. I'd be curious to see the mix you received last tank.
 

Zinc03svt

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I think you might have gotten a bad mix this round. That's the only explanation for it to do that all of the sudden. 3oz of the Lucas stabilizer should not affect 15 gallons of E85 in that manner. I'd be curious to see the mix you received last tank.
No kidding. Probably E45. Lol.

Thinking more about it I bet it is just the lower E85 winter blends. I did not drive the car as much either. The idle (occasional) issues started creeping up in the colder months. I did run a few logs and they look good past idle. Agreed, do not see the Lucas causing the said symptoms.
 

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E85 doesn't have the additives that quality 93 octane has. Something to keep in mind.
It has additives, but not the detergency. The corrosion inhibitors in it are specifically what causes deposits, and that is the reason you should run a detergent additive (or top tier 93oct) every once in a while.
 

stangman638

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Turns out my bank 1 sensor 1 o2 sensor was going bad, it threw a code eventually. I may stick with 93 since it seems like o2 sensors like to die on e85. p0030 was the code. Having the sensor replaced Monday.
Do you have long tubes or stock headers?
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