Page 267 - Manual_Polaris_RZR_ProXP-20-21

EFI / FUEL SYSTEM

FUEL INJECTORS
FUEL INJECTOR OPERATION FUEL INJECTOR O-RINGS
OVERVIEW 1. Any time an injector is removed, you must replace the
The fuel rail q, located on the intake manifold, retains upper and lower O-rings.
the fuel injectors w to the intake assembly. O-rings e on 2. Always lubricate NEW injector o-rings with clean,
both ends of the injectors prevent external fuel leaks and silicone-free motor oil.
also insulate the injectors from heat and vibration.
NOTICE
Apply oil sparingly and avoid contaminating the pintle
valve / jet surface and upper inlet port.

3. Install NEW o-rings onto top and bottom of injector

5

When the key switch is on, the fuel rail is pressurized,
and the EFI relay provides voltage to the injectors.
During engine operation, the ECU completes the ground
circuit, energizing the injectors. The valve needle in each
injector is opened electromagnetically, and the pressure
in the fuel rail forces fuel down through the inside. The
“director plate” at the tip of the injector contains a series ITEM PART COLOR POSITION
of calibrated openings which directs the fuel into the NUMBER
intake port in a cone-shaped spray pattern.
TOP OF
The amount of fuel injected is controlled by the ECU and q 5417103 Black INJECTOR
determined by the length of time the valve needle is held BOTTOM OF
open, also referred to as the “injection duration” or “pulse w 5417104 Brown INJECTOR
width”. It may vary in length depending on the speed and
load requirements of the engine.
IMPORTANT
The ECU gathers fuel injection timing information from Always install NEW o-rings when removing the fuel rail
the Crankshaft Position Sensor (CPS) and the Pedal or injectors.
Position Sensor (PPS) to allow for sequential fuel
injection.
IMPORTANT
Verify that the new top and bottom o-rings are installed
in the correct position and are lubricated with clean,
silicone-free oil.

9930583 R01 - 2020-2021 RZR PRO XP / XP 4 Service Manual 5.7
© Copyright Polaris Industries Inc.