I've noticed three or four threads recently with a common problem. EFI is appearing to be 'running to rich'. I wonder if there is a connection with the ethanol 'enhanced' fuels and something getting damaged....

Thoughts?

-Eric

Interesting theory. Would think it's hard to prove?

There is a gas station close to me thats been notorious for bad gas and suspicions of water in the fuel. Be careful!

I thought ethanol would make it lean cuz of the way it burns ? unless the computer is adding more fuel to overcome the lean from the Booze



Ryan

depends on how much ethanol is actually in the fuel, also

- Ethanol absorbs water and likes to deposit it in your fuel filter, also dropping the octane rating substantially,
- E10 drops in octane rating fairly rapidly after about a month and can even start to separate,
- E10 can perish Elastomer seals in your engine and fuel system

I believe it also has negative effects on softer metals such as copper and brass but can't remember 100%.

In my country regular gasoline is still available, if i was forced to run E10 would definitely get a water separator and install a filter of some description on the fuel tank breather to keep water/humidity out. In saying that though all my cars are so old that E10 would completely destroy them and eat pretty much all the moving parts anyway

Lambda is the ratio of a given AFR (air/fuel ratio) to the stoichiometric AFR for that fuel.
Lambda is what the O2 sensor is trying to keep the computer injecting, then we add
enrichments for acceleration and load situations to prevent pinging and engine damage as well
as for added power. that being said lambda for strait gasoline is 14.7:1 but best power is usually
obtained at 12.5:1 or in that range, turbo applications need that plus a half point to be safe.
That being understood, fuel mileage will suffer more with increasing amounts of ethanol mixed
into gasoline as stoichiometric AFR for ethanol is 9.0:1

E85 Ethanol has a 113 octane rating, Ethanol is the highest performance fuel on the market.
Yes ethanol likes to absorb water, and carry it right on through to the engine, check out the
gas drier bottles and you will find they are Methanol based additives to get rid of condensation
in your fuel tank. 

Wild

E85 Ethanol has a 113 octane rating, Ethanol is the highest performance fuel on the market.

I agree with you on the stoich properties of ethanol, but id hardly call it the highest performance fuel on the market, it may be alot cheaper than fuels of equal or better octane such as C14/15/16 but you can only take advantage of the octane rating in ethanol if your ecu is mapped to suit and your compression ratio/boost volume is high enough.

And after all that trouble you've still got 20-30% less energy per gallon than regular gasoline pushing you down the road.

But you'll be making less emissions, if thats what your into 

Yes but leaded fuels are a no-no in an EFI system unless you
are prepared to change the O2 sensor daily, lead coats and fouls
the sensor so I didn't use the racing fuel in my text

Wild

even so,

And after all that trouble you've still got 20-30% less energy per gallon than regular gasoline pushing you down the road.

But I don't know how readily available regular gasoline is in your area. In my country is getting near the stage of "unobtanium" now 

The lower BTU content of ethanol out weighs the postives of the higher octane rating in ethanol IMO

Yes, this is a problem, lower BTU content = less Miles per tank.

If I could get E-85 I would use it in the turbo SideKick, as alcohol
is very forgiving to over fueling, as much as 50% over fueling and
no loss of performance, I know that it would be dumb to over fuel
that much, but in a turbo application a little more than needed is
OK under boost, yet doesn't cause the poor running of Gasoline
in the same situation.

Methanol, to take advantage of the potential in that fuel needs
about 14:1 Compression ratio, non turbo application, with turbo
a standard 8.5 or 9.0:1 CR would work and take advantage of the
fuel, tho less energy per gallon, more overall power is available, at
a price of sacrificed miles per gallon for that fuel. Formula 1 uses
alcohol for fuel, there are good reasons to use it, power and emmisions
but mileage isn't one of them

Wild

But I don't know how readily available regular gasoline is in your area. In my country is getting near the stage of "unobtanium" now 

All gasoline in California is unleaded, unless it is racing gasoline or aviation fuel, both
are not legal for road going vehicles, as well as the problems with O2 sensors, so
yes it is unobtainium in these parts

Wild

I could see the advantages in a turbo setup using ethanol if unforeseen boost spikes are expected, or if the vehicle was previously naturally aspirated using a stock ecu with measures put in place to add more fueling such as a variable resistor on ecu water temp to increase fueling, or if the wastegate is too small - to give a safety margin to work with.

But more generally speaking, once said vehicle has been tuned through whatever means (aftermarket ecu perhaps), one would want it to stay in that state of tune, which is usually pretty close to stoich throughout the rev/load range ideally whatever stoich maybe for fuel used. I see no advantage in using more fuel than necessary, unless its compensation for lack of resolution throughout rev/load/temperature points.

a stock turbo application will not take advantage of ethanol octane rating unless it has either been retuned, or was tuned for such fuel from factory

and F1 gas is pretty far from what comes out of the pump at the gas station

Propane's supposed to be good for turbo too. 110 octaine isn't it?

Propane can vary from 100 to 130 in octane as far as I have heard