Ski-Doo FORMULA S 1997, Shop Manual

Page: 882 / 926

05-4
Section 05 DIGITAL PERFORMANCE MANAGEMENT (DPM) SYSTEM
Enrichment Mode (starting)
When turning the ignition key to the ON position,
the module is energized and goes on standby. The
module uses no electricity when on standby.
Once the engine begins to turn (using either the
electrical or rewind starter), the module receives
pulses through the MPEM (multi-purpose elec-
tronic module) ignition system GRAY/GREEN
wire.
The DPM module then comes on by reading the
engine temperature through the sensor located
on the cylinder head. The DPM module calculates
the enrichment solenoid opening time and the en-
richment rate according to the temperature. The
air/fuel mixture is then enriched in order to facili-
tate starting.
The system pressurizes all 3 carburetor bowls in
order to enrich the air/fuel mixture. This is accom-
plished with the help of an air pump.
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