On 1/2/2012 9:30 PM, JustWait wrote:
On 1/2/2012 8:35 PM, wrote:
On Mon, 02 Jan 2012 13:12:47 -0500, X `
wrote:

On 1/2/12 1:01 PM, wrote:
On Mon, 02 Jan 2012 10:04:24 -0700,
wrote:

On 01/01/2012 9:38 PM, Tim wrote:
On Jan 1, 10:22 pm, wrote:
On 01/01/2012 8:26 PM, Tim wrote:

http://www.boatingindustry.com/news/...nt-of-energy-e...


Yeah the article is 3 mo. old but it looks like the E15 is wrecking
havoc on even some 4-stroke marine engines.

I shudder the thought of what it would do to my chainsaws too.

Could have told you that 10 years ago. Real gas burns better and
does
less damage.

Oh I knew about it 10 years ago, but some people here might not see a
problem with it.

It's not good stuff especially for carburetor type engines.

While I think fuel injected engines handle it better, they too suffer.
I am in a high altitude area, and fuel millage is up but it should be
down. I suspect it is because we get the 100% gasoline.

But I am sure some congress people invested in ethanol.

Why would fuel mileage be down at a high altitude?


Just the opposite, no? Doesn't the 02 sensor detect exhaust gasses
getting richer as the oxygen in the air thins out, and therefore the
system drops back on the amount of gasoline burned so as to maintain the
proper mixture? If there is less oxygen and you burn less fuel, you get
less power but more miles per gallon? Alas, I am a mere English major,
so I doubt my "understanding" of the physics is correct.






You are correct! Between the O2 sensor and the Mass Flow Sensor, less
fuel will be fed to the engine to maintain the correct stochiometric
mixture. Summer and high altitude contribute to better fuel mileage,
though not necessarily maximum horsepower.

The O2 sensor is a "differentiator", which is to say it develops an
electrical charge based on the "difference" between external and
internal oxygen levels... Like I said before on such small engines there
isn't a lot of room for adjustment by the computer anyway, not to
mention the computer may not really have the capability to fully come to
a "zero or null base" to work it's calculations off of because of the
contradictory information coming from the MAP (manifold pressure)
sensor, and the O2... Just sayin'...

There is a moment in time when you first go to start your engine called
"key on, engine off" when the computer gets it's charge and looks at all
the sensors for their 0 (zero or null) reading. The IAC (idle air
control) for example is a small piston in the side of the intake which
bypasses the throttle body and makes micro adjustments to the air flow
to the intake while the gas pedal is off, and the throttle body is
closed. This is necessary with injected cars to allow for changes in
load from other equipment on the car, etc... The IAC has a capacity for
movement and that distance (the throw of the piston) is segmented into
256 units. When the vehicle enters that KOEO moment, the IAC closes all
the way and the computer notes where it bottomed out in along it's range
of motion of that 256. Let's say the piston bottoms out at positition 7,
the computer uses that setting as "zero" in it's calculations for the
remainder of the engine run... If there is **** and carbon in the IAC
for instance and it can't really zero out, the car will idle ****ty...

So, what does that have to do with the above post. In theory you could
make your car run better at higher altitude (or even after a storm front
came in, etc) by turning the car off once you reached high altitude, and
restart it to allow the car to "Zero" the O2, Manifold Absolute
Pressure, Ambient Baro Pressure, and the IAC valve to the ambient
conditions...

Ok, that's my nice post for today