Section 01: Injection System - APRILIA RSV Mille 1000 1999 Technical Training Course

Aprilia Consumer Service Spa
Technical Service and Training
Release 4 july 99

SECTION 01: INJECTION SYSTEM

1.1 PREFACE: INTRODUCTION ON THE INJECTION-IGNITION SYSTEM
The injection-ignition system is of the " alpha/n, D/J" type, in which motor speed and throttle
position are used as the main parameters for the quantity of aspirated air; knowing the quantity of
air, the fuel level is dosed as a function of the performance required. Other system sensor
atmospheric pressure, air temperature, water temperature allow basic settings to be corrected in
the event of specific conditions. In addition, motor speed and throttle angle allow the optimum spark,
advance to be calculated under any operating condition.
Electronic injection-ignition system.
The application of an electronic control injection-ignition system to eight-stroke-cycle engine,
optimizes their use, providing a higher specific horsepower together with a lower specific
consumption, and reducing the unburt elements in the exhaust gases. These advantages are got
thank to a more exact
equipment consists of three circuits: Fuel circuit, Sucked air circuit and Electric circuit.
Influence of air-fuel ratio and of spark advance.
Air-fuel ratio and spark advance are key factors for the optimum functioning of the engine, and so is
their management. The air-fuel ratio is fhe ratio of air and fuel (weight) supplied to the engine: the
ideal (stechiometric) ratio is achieved when full combustion is ensured. Too much or too little air will
produce a lean or rich mixture, respectively, which affects horse power and fueI consumption (see
fig. 1, as well as the pollutant content in exhaust emissions see fig. 2).
The electronic spark advance management optimises engine performance: peak power, transient,
consumption, pollution.
Fig.1
This material is didactic and
may be changed following the technical
development of the product
air-fuel ratio metering and a good spark advance control. This
Fig.2
1) Pollutants/ Polluants/ Umweltbelastende
Abgase /Contaminantes
2) Rich mixture / Melange riche / Reiches
Gemisch / Mezcla rica
3) Lean mixture / Melange pauvre / Armes
Gemisch / Mezcla pobre
4) Ideal ratio / Rapport ideal / Ideales Verhaltnis /
Proporcion ideal