Electronic Fuel Injection; Fuel System Operation Overview; Initial Priming / Starting Procedure - Polaris RANGER XP 900 2018-2019 Service Manual

FUEL SYSTEM

ELECTRONIC FUEL INJECTION

FUEL SYSTEM 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
performance.
The central component of the system is the Bosch ME17
Electronic Control Unit (ECU) which manages system
operation, determining the best combination of fuel
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. A fuel
pressure regulator located in the tank maintains system
operating pressure. At the engine, fuel fed to 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 of the 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.
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 pedal 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.
4.6
to maintain peak
9929399 R01 - 2018-2019 RANGER XP/ CREW 900/1000 Service Manual

INITIAL PRIMING / STARTING PROCEDURE

NOTICE
The injection system must be purged of all air prior to
the initial start up, and / or any time the fuel system has
been disassembled.
If the fuel system is completely out 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, turn the key switch to
"START" until the engine starts or 5 seconds has
passed.
3. If the engine failed to start, repeat step 1 for 2 more
cycles and attempt to start the engine.
If the engine fails to start, a problem may still exist,
and should be diagnosed.
NOTICE
Accurate testing of EFI components is recommended
utilizing the Digital Wrench® Diagnostic Software
(dealer only).
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