Fuel Injector; Fuel Injector Operation Overview; Fuel Injector Overview; Fuel Injector O-Rings - Polaris GENERAL 2016 Service Manual

FUEL INJECTOR

FUEL INJECTOR OPERATION OVERVIEW

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The fuel rail , located on the intake manifold, retains
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the fuel injectors to the intake assembly. O-rings on
both ends of the injectors 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". It may vary in length depending on the speed and
load requirements of the engine.
The ECU gathers fuel injection timing information from
the Crankshaft Position Sensor (CPS) and the Pedal
Position Sensor (PPS) to allow for sequential fuel
injection.
9929375 R02 - 2016-2019 GENERAL / GENERAL 4 Service Manual
© Copyright Polaris Industries Inc.

FUEL INJECTOR OVERVIEW

q
The fuel injector is mounted into the cylinder head,
w
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". It may vary in length depending on the speed and
load requirements of the engine.
The ECU gathers fuel injection timing information from
the Crankshaft Position Sensor (CPS) and the Pedal
Position Sensor (PPS) to allow for sequential fuel
injection.

FUEL INJECTOR O-RINGS

1. Any time an injector is removed, you must replace the
upper and lower O-rings.
2. Always lubricate NEW injector o-rings with clean,
silicone-free motor oil.
NOTICE
Apply oil sparingly and avoid contaminating the pintle
valve / jet surface and upper inlet port.
FUEL SYSTEM
4
4.25