Initial Priming Istarting Procedure - Polaris Ranger RZR XP 900 2011 Service Manual

ELECTRONIC FUEL INJECTION
ELECTRONIC FUEL INJECTION
Principal Components
The Electronic Fuel Inj ection (BFI) system is a complete engine
fuel and ignition management design. This system includes the
following principal components:
• Check Engine Light
• Crankshaft Position Sensor (CPS)
• Dual Throttle Body / Intake Adapter
• Engine Control Unit (ECU)
• Engine Coolant Temperature Sensor (ECT)
• Fuel Filter(s)
• Fuel Injectors
• Fuel Pressure Regulators
• FuelPump
• Fuel Rail
• Fuel Supply/Return Lines
• Idle Air Control Valve (IAC)
• Ignition Coil
• Manifold Air Quality Sensor (MAQS)
• Wire Harness Assembly
EFI Operation Overview
The EFI system is designed to provide peak engine performance
with optimum fuel efficiency and lowest possible emissions.
The ignition and injection functions are electronically
controlled, monitored and continually corrected during
operation to maintain peak performance.
The central component of the system is the Bosch M17
Electronic Control Unit (BCU) which manages system
operation, determining the best combination offuel mixture and
ignition timing for the current operating conditions.
An electric fuel pump is used to move fuel from the tank,
through the fuel supply line, to the fuel rail. Fuel pressure
regulators located in the tank and on the end of the fuel rail,
maintain system operating pressure and return excess fuel back
into the fuel tank. At the engine, fuel fed through the fuel rail
supplies fuel to the injectors, which inject into the intake ports.
The ECU controls the amount of fuel by varying the length of
time that the injectors are "on." This range can vary depending
on fuel requirements. The controlled injection ofthe fuel occurs
every other crankshaft revolution, or once for each 4-stroke
cycle. When the intake valve opens, the fuel/air mixture is
drawn into the combustion chamber, ignited and burned.
4.12
The ECU controls the amount of fuel being injected and the
ignition timing by monitoring the primary sensor signals for
intake air temperature, manifold absolute pressure (load),
engine temperature, engine speed (RPM) and throttle position.
These primary signals are compared to the programming in the
ECU computer chip, and the ECU adjusts the fuel delivery and
ignition timing based on these values.
During operation, the ECU has the ability to re-adjust
temporarily; providing compensation for changes in overall
engine condition and operating environment, so it will be able
to maintain the ideal air/fuel ratio.
During certain operating periods such as cold starts, warm up,
acceleration, etc., a richer air / fuel ratio is automatically
calculated by the ECU.
Initial Priming
I
Starting Procedure
NOTE: The injection system must be purged of all
air prior to the initial start up, and I or any time the
system has been disassembled.
If the EFI system is completely empty of fuel or has been
disassembled and repaired:
1. Cycle the key switch from "OFF" to "ON" 6 times, waiting
for approximately 3 seconds at each "ON" cycle to allow
the fuel pump to cycle and shut down.
2. Once step 1 is completed,
tum
the key switch to "START"
until the engine starts or 5 seconds has passed.
3. Ifthe engine failed to start, repeat step 1 for 2 more cycles
and attempt to start the engine.
Ifthe engine fails to start, a problem may still exist, and should
be diagnosed.
NOTE: Accurate testing of EFI components is
recommended utilizing the Digital Wrench™
Diagnostic Software (dealer only).
9923144 - 2011 RANGER RZR XP 900 Service Manual
© Copyright 2011 Polaris Sales Inc.