Posted by z on August 14, 2008, 11:12 am
clare at snyder dot ontario dot canada wrote in
>
>>
>>>
>>>>
>>>>
>>>> z wrote:
>>>>
>>>>> Hmm. When its rolling down the hills its in idle
>>>>
>>>> I.e using fuel. Wastefully.
>>>>
>>>>> -- when its in gear it revs.
>>>>
>>>> But uses no fuel if supplying braking. I've seen it on my own mpg
>>>> meter.
>>>>
>>>> That the beauty of modern electronics.
>>>>
>>>> You need to wake your ideas up.
>>>
>>> Of course, that may vary depending on the car. Mine has more engine
>>> braking if you turn off the ignition (fuel injected), so it is using
>>> some fuel even when coasting in gear, if the ignition is on. I
>>> suppose it might use slightly more at higher rpms, just because it
>>> inject some gas with every revolution.
>>>
>>>
>>>
>>
>>right. Some fuel is being used per RPM otherwise the car would die
>>right?
>
> Nope. The injectors shut off and the engine is backdriven by the
> transmission. At a certain speed it comes back on to prevent stalling.
>>
>>Why would a car at idle use less fuel than the same car at 2500 RPM?
>>Man them computer things are smart!!
>>
>>Anyway, i'm living in the 70's with kugelfischer injection systems,
>>where the computer is a fuel curve cone :)
>
> Kjet? Or K-Jet Lamda? K-Jet Lamda (KE Jet?) system on SOME cars
> virtually shut off fuel on Decel by energizing the Frequency Valve
The Kugelfischer was an early mechanical fuel injection (much like a
diesel) used by BMW and a few others (opel?). Its much like an alfa
SPICA
Read All About it!
http://www.bmw2002faq.com/content/view/66/32/
I like the system because the fuel is very high pressure and the entire
system is purely mechanical .. the only circuit is the thermo-timer that
runs the cold start injector (which most people end up bypassing to a
button as those boards are hard to replace when they go bad).
A well timed and tuned KF injection setup on an m10 engine is a wonder to
behold.
I'll take your guys word about the more modern systems.. Sometimes I
forget i'm in the 21st century :)
-zachary
Posted by Eeyore on August 13, 2008, 11:10 pm
Bob F wrote:
> > z wrote:
> >
> >> Hmm. When its rolling down the hills its in idle
> >
> > I.e using fuel. Wastefully.
> >
> >> -- when its in gear it revs.
> >
> > But uses no fuel if supplying braking. I've seen it on my own mpg meter.
> >
> > That the beauty of modern electronics.
> >
> > You need to wake your ideas up.
> Of course, that may vary depending on the car. Mine has more engine braking if
> you turn off the ignition
Illegal in the UK. And a sign that the mapping (or some other aspect) is poor.
> (fuel injected), so it is using some fuel even when
> coasting in gear, if the ignition is on. I suppose it might use slightly more
at
> higher rpms, just because it inject some gas with every revolution.
Who makes the ECU in your car ? I'll bet it's not Bosch or Saab.
Graham
Posted by Bruce Richmond on August 14, 2008, 10:51 pm
wrote:
> Bob F wrote:
> > > z wrote:
> > >> Hmm. When its rolling down the hills its in idle
> > > I.e using fuel. Wastefully.
> > >> -- when its in gear it revs.
> > > But uses no fuel if supplying braking. I've seen it on my own mpg meter.
> > > That the beauty of modern electronics.
> > > You need to wake your ideas up.
> > Of course, that may vary depending on the car. Mine has more engine braking if
> > you turn off the ignition
> Illegal in the UK. And a sign that the mapping (or some other aspect) is poor.
> > (fuel injected), so it is using some fuel even when
> > coasting in gear, if the ignition is on. I suppose it might use slightly more at
> > higher rpms, just because it inject some gas with every revolution.
> Who makes the ECU in your car ? I'll bet it's not Bosch or Saab.
> Graham- Hide quoted text -
> - Show quoted text -
My 1981 Dodge Colt (Mitsubishi) had an electrically controled valve to
shut the fuel off if the vacume was high and the revs above idle, and
it used a carb.
Posted by Eeyore on August 13, 2008, 7:41 pm
Bob F wrote:
> If you need to use the brakes, put it in gear. Downshift as needed. No sense in
> being out-of-gear if you need to slow down anyway. It won't save any fuel over
> using the natural engine braking.
Using the engine as a brake is vastly more efficient.
Old wives' tales like this persist only from the carburettor era when even then
it
was doubtful it did much good.
Graham
Posted by Trygve Lillefosse on August 13, 2008, 3:12 pm
>>
>>
>> Arumugham wrote:
>>
>>> Maintain required tyre pressure.
>>> Maintain uniform and economic speed as far as possible using
>>> appropriate gear.
>>> Accelerate and retardate slow in general.
>>
>> Avoid unnecessaryly harsh use of brakes in particular. Use natural
>> slowing down as far as possible.
>>
>>
>>> Avoid abrupt braking.
>>> Anticipate traffic conditions.
>>
>> Totally.
>>
>> Also for best economy try as far as possible to maintain a constantish
>> speed on long runs.
>>
>> Graham
>>
>I'm able to coast down hills in neutral for six of the 16 mile round trip
>I make to town.
>Harder on brakes but I just put new pads on so they'll be good for a
>while.
>I figure thats got to be saving gas.
If you got an engine with injection, you will use less if you keep it
in gear.
--
SEE YA !!!
Trygve Lillefosse
AKA - Malawi, The Fisher King
XML site map
>>
>>>
>>>>
>>>>
>>>> z wrote:
>>>>
>>>>> Hmm. When its rolling down the hills its in idle
>>>>
>>>> I.e using fuel. Wastefully.
>>>>
>>>>> -- when its in gear it revs.
>>>>
>>>> But uses no fuel if supplying braking. I've seen it on my own mpg
>>>> meter.
>>>>
>>>> That the beauty of modern electronics.
>>>>
>>>> You need to wake your ideas up.
>>>
>>> Of course, that may vary depending on the car. Mine has more engine
>>> braking if you turn off the ignition (fuel injected), so it is using
>>> some fuel even when coasting in gear, if the ignition is on. I
>>> suppose it might use slightly more at higher rpms, just because it
>>> inject some gas with every revolution.
>>>
>>>
>>>
>>
>>right. Some fuel is being used per RPM otherwise the car would die
>>right?
>
> Nope. The injectors shut off and the engine is backdriven by the
> transmission. At a certain speed it comes back on to prevent stalling.
>>
>>Why would a car at idle use less fuel than the same car at 2500 RPM?
>>Man them computer things are smart!!
>>
>>Anyway, i'm living in the 70's with kugelfischer injection systems,
>>where the computer is a fuel curve cone :)
>
> Kjet? Or K-Jet Lamda? K-Jet Lamda (KE Jet?) system on SOME cars
> virtually shut off fuel on Decel by energizing the Frequency Valve