Page 202 - Manual Oficina Polaris RZR XP 1000 17-18

FUEL SYSTEM

• Fuel Pump (RPM) and throttle position. These primary signals are
compared to the programming in the ECU computer chip,
• Fuel Rail
and the ECU adjusts the fuel delivery and ignition timing
• Fuel Supply/Return Lines based on these values.
• Idle Air Control Valve (IAC) During operation, the ECU has the ability to re-adjust
temporarily; providing compensation for changes in
• Ignition Coil
overall engine condition and operating environment, so it
• Temperature and Manifold Pressure Sensor (TMAP) will be able to maintain the ideal air/fuel ratio.
• Wire Harness Assembly During certain operating periods such as cold starts,
warm up, acceleration, etc., a richer air / fuel ratio is
automatically calculated by the ECU.
EFI OPERATION OVERVIEW
The EFI system is designed to provide peak engine INITIAL PRIMING / STARTING PROCEDURE
performance with optimum fuel efficiency and lowest
possible emissions. The ignition and injection functions NOTICE
are electronically controlled, monitored and continually The injection system must be purged of all air prior to
corrected during operation to maintain peak the initial start up, and / or any time the system has
performance.
been disassembled.
The central component of the system is the Bosch ME17
Electronic Control Unit (ECU) which manages system If the EFI system is completely empty of fuel or has been
operation, determining the best combination of fuel disassembled and repaired:
mixture and ignition timing for the current operating 1. Cycle the key switch from “OFF” to “ON” 6 times,
conditions.
waiting for approximately 3 seconds at each “ON”
An electric fuel pump is used to move fuel from the tank, cycle to allow the fuel pump to cycle and shut down.
through the fuel supply line, to the fuel rail. Fuel pressure
regulators located in the tank and on the end of the fuel 2. Once step 1 is completed, turn the key switch to
rail, maintain system operating pressure and return “START” until the engine starts or 5 seconds has
excess fuel back into the fuel tank. At the engine, fuel fed passed.
through the fuel rail supplies fuel to the injectors, which 3. If the engine failed to start, repeat step 1 for 2 more
inject into the intake ports. The ECU controls the amount cycles and attempt to start the engine.
of fuel by varying the length of time that the injectors are If the engine fails to start, a problem may still exist,
"on." This range can vary depending on fuel and should be diagnosed.
requirements. The controlled injection of the fuel occurs
every other crankshaft revolution, or once for each 4- NOTICE
stroke cycle. When the intake valve opens, the fuel/air
mixture is drawn into the combustion chamber, ignited Accurate testing of EFI components is recommended
and burned. utilizing the Digital Wrench® Diagnostic Software
(dealer only).
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

4.8 9928492 R06 - 2017-2018 RZR XP 1000 / XP4 1000 Service Manual
© Copyright Polaris Industries Inc.