Page 353 - Manual Oficina Polaris Sportsman 570 2014 a 2016

FUEL SYSTEM

FUEL INJECTOR

FUEL INJECTOR - 325 FUEL INJECTOR TEST
The fuel injector is non-serviceable. If diagnosis indicates
a problem with the injector, test the resistance of the fuel
injector solenoid windings by measuring between the two
terminals e:

4

FUEL INJECTOR - 570

Fuel Injector Resistance Specification:
11.4 - 12.6 Ω

FUEL INJECTOR OVERVIEW
The fuel injector is mounted into the cylinder head, with
the fuel rail retaining it from the top end. O-rings on both
ends of the injector prevent external fuel leaks and also
insulate the injectors from heat and vibration.
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
of calibrated openings which directs the fuel into the
intake port in a cone-shaped spray pattern.
The amount of fuel injected is controlled by the ECU and
determined by the length of time the valve needle is held
open, also referred to as the “injection duration” or “pulse
width modulation”. It may vary in length depending on the
speed and load requirements of the engine.

9926803 R06 - 2014-2016 Sportsman 325 / ETX / 450 HO / 570 Service Manual 4.37
© Copyright Polaris Industries Inc.