MOTO GUZZI V 11 SPORT, Workshop Manual

Page: 194 / 412

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2 F
UEL SYSTEM
1 GENERAL DESCRIPTION OF THE
SYSTEM
The Weber injection-ignition system is an “alfa/N” type in
which the engine r.p.m. and the throttle position are used
to measure the quantity of air taken in; knowing the air
quantity, the fuel quantity is measured according to the
desired mixture ratio. Other sensors in the system allow
the basic strategy to be adjusted under particular operating
conditions.
The engine r.p.m. and the throttle angle make it possible
to calculate the optimal spark advance for any operating
condition.
The quantity of air taken in by each cylinder, per each
cycle, depends on the density of air in the manifold, on
the single displacement and on the volumetric efficiency.
The volumetric efficiency is determined experimentally
on the engine over the whole operating range (r.p.m. and
engine load) and it is stored in a map inside the ECU.
The injector control, per cylinder, is a “timed sequence”
type control; this means that the two injectors are controlled
according to the intake sequence, while each cylinder
supply can start directly from the expansion stage up to
the already begun intake stage. The timing for the supply
start is contained in a map inside the ECU.
The ignition is an inductive discharge static type with dwell
control in the power modules (incorporated in the ECU)
and a mapping of the spark advance stored in the ECU.
The coils receive the commands from the ECU I.A.W. 15
M, which processes the spark advance, through the power
modules (incorporated in the ECU).
The Weber Marelli 1.5 injection/ignition system main
feature lies in the fact that it can be adjusted and
diagnosed only through a special software. This can
be ordered from the Motor Guzzi spare parts
headquarters, quoting code no. 00 97 97 15.
This computer programme is called “Motorbike
Diagnostic Software Toll” and can be installed on any
PC (min. requirements 486 DX2 33Mhz). By connecting
the latter through a special hardware key directly to
the ECU, the software allows the user to adjust the
carburation and the system diagnostics; for a detailed
description about the programme use, please consult
the user manual supplied with the software package.
2 SYSTEM COMPONENTS
The system is composed of three circuits:
A fuel circuit
B intake air circuit
C electrical circuit