Polaris Virage TX 2000 Service Manual page 278

FFI™ FUEL INJECTION
Theory
FFI™ FUEL INJECTION DIAGNOSTIC SOFTWARE: PN 2873377
Overview
The function of Polaris' FFI ™ (Ficht® Fuel Injection) model sequential, direct-injection fuel system is to efficiently
supply fuel under all engine load, temperature, and RPM conditions. The benefits of FFI ™ include quick starting,
improved fuel economy, excellent throttle response, and greatly reduced exhaust emissions. FFI ™ involves the
interaction of various fuel, ignition, and electrical components. All these components work together under the
direction of an EMM (Engine Management Module).
A WARNING
It is unlawful to tamper with any system or function of Polaris FFI™ model personal watercraft. Do not
modify any part of the watercraft. Doing so may end in a fine and/or jail.
Polaris' FFI ™ system has a number of unique features:
• Alternator output is dual-voltage; both 12 and 38 to 45 volts DC are produced and regu
lated.
• The fuel injectors are a German concept (Ficht®); fuel is injected under high pressure
directly into each combustion chamber.
• The fuel system is protected by a water separating filter which is located in the fuel tank.
• Technician diagnostic procedures are simple; the EMM stores service codes and deliv
ers real-time data.
• Various sensors monitor engine running conditions; operator warning systems like
S.L.O.W.™ are standard features.
• The ignition system is a high-frequency multi-strike CD system that generates a variable
spark profile to exactly meet combustion requirements.
• The EMM is water cooled, and controls the ignition coils' primary circuit operation.
Fuel Injectors
The fuel injectors are in a 38-45 volt system, and there is one injector per cylinder. The injectors are secured to
the cylinder head by a flange and two bolts. Each injector has two ports; one for fuel inlet(large port on bottom),
the other an outlet(smaller port on top), both on the same side of the injector body. The inlets and outlets are
different sizes to prevent fuel line mis-installation.
The EMM controls injector operation by opening and closing individual injector ground circuits. In doing so, the
EMM can change both the timing and duration of the fuel charge (pulse width). The EMM adjusts injector opera
tion in respect to data received from various engine sensors. It also senses changes in the 45 volt circuit from
the rectifier/regulator inside the EMM.
Each injector has an internal fuel passage designed for cooling. Fuel passes through the body to link the inlet
and outlet nipples. Since fuel arrives under pressure, a small volume constantly flows through the injector to cool
the armature. Fuel pressure to the injectors is approximately 25 psi.
If a fuel injector electrical circuit becomes open or disconnected while the engine is running, the EMM will store
a specific injector service code in memory, and will turn on the "check engine" light.
Ignition System Operation
Polaris' FFI ™ ignition system is a high frequency, multi-strike CD system that generates a variable spark profile
to exactly meet combustion requirements. AC current is generated by the stator, passed through the regulator
inside the EMM for conversion to DC. Signals from the crank position sensor allow the EMM to determine proper
cylinder firing sequence. Internal circuits also allow the EMM to detect open loads in the coil primary circuits, and
set and store corresponding service codes.
Polaris Sales Inc. 8.1 3/00