Arctic Cat Sno Pro 120 2011, Service Manual

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4-14
Fuel System (EFI)
Table of Contents
Arctic Cat EFI System ........................................... 4-14
Individual EFI Components ................................... 4-15
Self-Diagnostic EFI System/Codes ....................... 4-17
Testing Individual Components ............................. 4-18
Throttle Body Assembly ........................................ 4-21
Throttle Body Flange............................................. 4-27
Throttle Cable........................................................ 4-28
Voltage/Resistance Chart - Air Temperature......... 4-29
Voltage/Resistance Chart - Coolant Temperature. 4-29
Troubleshooting Fuel System................................ 4-30
Arctic Cat EFI System
INTRODUCTION
The EFI system is lightweight in design and is made up
of a number of components explained in this sub-section.
The EFI system has the following features:
1. Automatic compensation for temperature.
2. Automatic compensation for altitude.
3. Optimum throttle response through high pressure
injection.
4. Quick starting in every condition.
5. Improved fuel efficiency with maximum mileage in
every condition.
6. Engine RPM more stable in every condition.
The Arctic Cat EFI System operates off a series of coils
located on the stator and is made up of the following
components.
1. Charge coils (1 and 2), located on the stator, provide
AC voltage to the ECU/CCU/regulator/rectifier
where AC voltage is converted to DC voltage.
2. A fuel pump coil located on the stator operates the
low voltage, high output fuel pump. At cranking
speed, the high output fuel pump provides enough
fuel to charge the fuel rail.
3. An injector coil located on the stator provides the
injectors with DC voltage for operation through the
ECU.
4. A lighting coil located on the stator plate provides
output to the CCU/regulator/rectifier to operate
accessories and the lighting system.
5. An electrical control unit (ECU) calculates input
from sensors (air temperature sensor, coolant tem-
perature sensor, throttle position sensor, ignition tim-
ing sensor (2-stroke), barometric pressure sensor (2-
stroke), and on the 800/1100 cc, a knock sensor) to
provide the engine with the correct fuel mixture and
timing for optimum operation.
PRECAUTIONS
729-325A
FLOODED ENGINE
If the engine should become flooded, set the brake lever
lock, compress the throttle lever to the full-open position,
and crank the engine over until it starts and clears itself.
Release the brake lever lock.
FUEL SYSTEM
The EFI fuel system consists of the following compo-
nents.
1. Gas tank
2. Electric high output fuel pump
3. Pick-up valves with micron screens
4. High-pressure fuel hose
5. Fuel rail
6. Fuel pressure regulator
7. Throttle body assembly
8. Fuel injectors
9. ECU
These components are grouped into the fuel handling
system. They work together along with electrical sensors
(following list) and the ECU to provide the engine with a
precise fuel mixture for combustion.
1. Ignition Timing Sensor (2-stroke)
2. Air Temperature Sensor
3. Coolant Temperature Sensor
! WARNING
Whenever working on the fuel system if a fuel hose is
removed from any component, slowly bleed the pres-
sure from the hose into an absorbent towel before
removing the hose from the component.
! WARNING
Always tighten fuel hose clamps securely.
CAUTION
Always use resistor-type spark plugs and spark plug
caps. Non-resistor components will cause the ECU to
malfunction.
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