Page 195 - Manual Oficina Polaris RZR 570 13-18

FUEL SYSTEM

EFI OVERVIEW

PRINCIPAL COMPONENTS the programming in the ECU computer chip, and the
ECU adjusts the fuel delivery and ignition timing to match
The Electronic Fuel Injection (EFI) system is a complete
engine fuel and ignition management design. This the values.
system includes the following principal components: During operation, the ECU has the ability to re-adjust
temporarily; providing compensation for changes in
• Fuel Pump overall engine condition and operating environment, so it
• Fuel Rail will be able to maintain the ideal air/fuel ratio.
• Fuel Line
• Fuel Filter(s) During certain operating periods such as cold starts,
• Fuel Injector warm up, acceleration, etc., a richer air / fuel ratio is
• Pressure Regulators automatically calculated by the ECU.
• Throttle Body / lntake Manifold
• Engine Control Unit (ECU) INITIAL PRIMING / STARTING PROCEDURE
• Ignition Coils
• Engine Coolant Temperature Sensor (ECT) NOTE 4
• Throttle Position Sensor (TPS) The injection system must be purged of all air prior to
• Crankshaft Position Sensor (CPS) the initial start up, and / or any time the system has
• Temperature and Manifold Absolute Pressure Sensor been disassembled.
(T-MAP)
• Idle Air Control Motor (IAC) If the EFI system is completely empty of fuel or has been
• Wire Harness Assembly disassembled and repaired:
• Check Engine Light
1. Cycle the key switch from “OFF” to “ON” 6 times,
waiting for approximately 3 seconds at each “ON”
EFI OPERATION OVERVIEW cycle to allow the fuel pump to cycle and shut down.
The EFI system is designed to provide peak engine 2. Once step 1 is completed, turn the key switch to
performance with optimum fuel efficiency and lowest “START” until the engine starts or 5 seconds has
possible emissions. The ignition and injection functions passed.
are electronically controlled, monitored and continually
corrected during operation to maintain peak 3. If the engine failed to start, repeat step 1 for 2 more
performance. cycles and attempt to start the engine.
The central component of the system is the Bosch If the engine fails to start, a problem may still exist,
Electronic Control Unit (ECU) which manages system and should be diagnosed.
operation, determining the best combination of fuel
mixture and ignition timing for the current operating NOTE
conditions. Accurate testing of EFI components is recommended
An in-tank electric fuel pump is used to move fuel from utilizing the Digital Wrench® Diagnostic Software
the tank through the fuel line, to the fuel rail. The in-tank (dealer only).
fuel pressure regulator maintains a system operating
pressure and returns any excess fuel back into the tank.
At the engine, fuel is fed through the fuel rail and into 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. The total amount of fuel
needed for one firing of a cylinder is injected during each
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, speed (RPM), and
throttle position. These primary signals are compared to

9926813 R06 - 2013-2016 RZR 570 Service Manual 4.9
© Copyright Polaris Industries Inc.