Owner`s manual

To get the most from an engine—in the way
of performance, smooth driveability, economy
and control of harmful emissions—a number
of decisive factors must be controlled as
precisely as possible under all driving condi-
tions. These ‘‘factors’’ include the following:
O The timing and overlap of the intake and
exhaust valves in relation to the position of
the pistons in the engine.
O The mixture of air and fuel that enters the
engine cylinders during each intake stroke
of the pistons.
O The timing of the spark that ignites the
pressurized charge of air and fuel near the
end of the compression stroke of the
pistons.
O The temperature of the combustion that
occurs in the cylinders, especially under
load.
O Engine idle speed under all conditions.
The engine in your INFINITI has degrees of
precision in the automatic control of these
factors that, only a few years ago, were not
thought possible by any known technology.
Such a high performance engine must operate
smoothly and efficiently at all speed. And it
must do so with a minimum of fuel consump-
tion and a minimum of emissions into the
environment.
MIXTURE CONTROL
A gasoline engine requires a relatively ‘‘rich’’
mixture of fuel to air during idle, a ‘‘lean’’
mixture for mid-range and ‘‘cruise’’ condi-
tions, and a ‘‘richer’’ mixture for high load,
high RPM operation. The changes in amount
of fuel delivered to the engine must occur
smoothly, sometimes in response to sudden
changes in demand from the driver. The
INFINITI ECCS can give the engine precisely
the amount of fuel required for each condition,
according to a precise measurement of the
amount of air that is allowed into the engine
either through automatic devices provided for
idle control or in response to your foot
pressure on the vehicle throttle.
All of the atmospheric air that is drawn into
the engine is measured by a mass air flow
sensor.
This type of mass air flow sensor can respond
very quickly to changes in intake air quantity
and density, which means as you step on the
throttle of your INFINITI to move into freeway
traffic, a voltage signal is sent to the ECM
(engine control module) instantly, and the
ECM responds just as quickly to provide more
fuel by allowing the port fuel injectors to stay
open precise milliseconds longer. The result
is smooth acceleration, without ‘‘stumble’’ or
‘‘hesitation’’.
TECHNICAL AND CONSUMER INFORMATION
9-4
Z 96.12.20/ X