Etanol.nu

hej hej,

does anyone know at which engine speed (rpm) the Lambda regulation switches off?

background: in the German forum ethanol-tanken.com there is a user whose car has a Lambda switch off at 3000 rpm!!

does that mean that above 3000 rpm there is no engine regulation at all = only a fix fuel volume injected?

i guess that 3000rpm is a very low value, isn't it?

my car just drives 120 km/h at that value

_________________
best wishes from here
Volvo V70 II on 30% E85 (just for starts) and LPG
Berti
http://www.ethanol-tanken.com
http://www.spritmonitor.de/de/detailansicht[url]/349366.html[/url]

No, the lambda control is (normally) never switched off at a certain rpm.

Usually, it is switched off on the following conditions:

-Full throttle, on a Volvo with LH 2.4.x this is controlled by a switch at the throttle shaft but on other cars it might be controlled by an analog throttle position sensor or by a pressure sensor/switch in the intake manifold.

-Cold engine. After a cold start, the lambda control cannot be switched on before the engine is so warm that is does not need any cold running enrichment. In some cases, this is only controlled by engine temperature, in other cases it might be controlled by a combination of temperature and time. Furthermore, the lambda sensor must have reached operation temperature, which can take some time on cars without electric preheating of the sensor.

-Overrun braking (coasting). As the fuel is normally cut off during this condition, there is no use to have the lambda control running.

Some early american cars with lambda control had a so-called highway mode, where the lambda control was switched off and the engine allowed to run on a lean mixture after some minutes of driving at constant highway speed.

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the switch off at full throttle is a must-be, or the engine will run lean!
...but do you know a value, i.e. at 6000 rpm?

cold engine: yeah, in my Volvo there is a temp measure unit connected to the LH 2.4.
during cold running there is an enrichment, as far as i know only controlled by temperature. in case of driving with E85 this causes some little problems, i.e. the increasing the speed is at a low level, jsut my feeling.

_________________
best wishes from here
Volvo V70 II on 30% E85 (just for starts) and LPG
Berti
http://www.ethanol-tanken.com
http://www.spritmonitor.de/de/detailansicht[url]/349366.html[/url]

No, the full load enrichment is not dependent of the rpm but of the full-throttle switch. So, the engine will go out of lambda control even if you give full throttle at, say, 1000 rpm. But if you run it unloaded at 6000 rpm with a small throttle opening, then it will run with lambda control.


I have recently noted that factory-built FFV cars, for instance Ford Focus, do not have any full load enrichment as usual on gasoline engines. Those run with lambda control even at full throttle.

There are also a few gasoline engines where full load enrichment doesn't seem to be necessary. For instance, the 1,7 l and 1,8 l air-cooled engines with L-jetronic in VW Transporter have no full load enrichment while the 2,0 l engines do have.

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