Aprilia Consumer Service Spa
Technical Service and Training
Release 4 july 99
This material is didactic and
may be changed following the technical
development of the product
Operation phases.
NORMAL OPERATION
When the engine has a normal temperature, the control unit –ECU- calculates the phase, the
injection time and the spark advance through interpolation of the corresponding store maps, as
function of the r.p.m/pressure (..and other input)
STARTING PHASE
When the ignition switch is operated, the control unit feeds the fuel pump for a few seconds and
receives the throttle opening angle and engine temperature signals. At the start, the control unit
receives the engine revolutions and phase signals, which allow the injection and ignition control. To
make the starting easier, in addition to the use of the Starter, the base metering is enriched,
conforming to the coolant temperature.
OPERATION DURING ACCELERATION/DECELERATION
During acceleration, the system increases the delivered fuel amount, so to have a better driving.
The acceleration condition is detected when the throttle opening angle increases remarkably; the
enrichment factor will be proportional to the pressure change and to the cooling water temperature.
A decrease of the throttle opening angle shows a deceleration and causes a reduction of the
delivered fuel.