Page 180 - Manual Oficina XP 1000 14-16

FUEL SYSTEM

FUEL INJECTORS

OPERATION OVERVIEW FUEL INJECTOR TROUBLESHOOTING
The fuel rail q, located on the intake manifold, retains Injector problems typically fall into three general
the fuel injectors w to the intake assembly. O-rings on categories- electrical, dirty / clogged, or leakage. An
both ends of the injectors prevent external fuel leaks and electrical problem usually causes one or both of the
also insulate the injectors from heat and vibration. injectors to stop functioning. Several methods may be
used to check if the injectors are operating.

• With the engine running at idle, feel for operational
vibration, indicating that they are opening and closing.
• When temperatures prohibit touching, listen for a
buzzing or clicking sound with a screwdriver or
mechanic's stethoscope.
• Disconnect the electrical connector from an injector
and listen for a change in idle performance (only
running on one cylinder) or a change in injector noise
or vibration.
NOTE
Do not apply voltage directly to the fuel injector(s).
Excessive voltage will burn out the injector(s). Do not
ground the injector(s) with the ignition on. lnjector(s) will
open/turn on if relay is energized.
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 If an injector is not operating, it can indicate either a bad
circuit, energizing the injectors. The valve needle in each injector, or a wiring/electrical connection problem. Check
injector is opened electromagnetically, and the pressure as follows:
in the fuel rail forces fuel down through the inside. The
“director plate” at the tip of the injector contains a series Injector leakage is very unlikely, but in rare instances it
of calibrated openings which directs the fuel into the can be internal (past the tip of the valve needle), or
intake port in a cone-shaped spray pattern. external (weeping around the injector body). The loss of
system pressure from the leakage can cause hot restart
The amount of fuel injected is controlled by the ECU and problems and longer cranking times.
determined by the length of time the valve needle is held
open, also referred to as the “injection duration” or “pulse Injector problems due to dirt or clogging are unlikely due
width”. It may vary in length depending on the speed and to the design of the injectors, the high fuel pressure, the
load requirements of the engine. use of filters and the detergent additives in the gasoline.
Symptoms that could be caused by dirty/clogged
The ECU gathers fuel injection timing information from injectors include rough idle, hesitation/stumble during
the Crankshaft Position Sensor (CPS) and the Pedal acceleration, or triggering of fault codes related to fuel
Position Sensor (PPS) to allow for sequential fuel delivery. Injector clogging is usually caused by a buildup
injection. of deposits on the director plate, restricting the flow of
fuel, resulting in a poor spray pattern. Some contributing
factors to injector clogging include; dirty air filters, higher
than normal operating temperatures, short operating
intervals and dirty, incorrect, or poor quality fuel.
Cleaning of clogged injectors is not recommended; they
should be replaced. Additives and higher grades of fuel
can be used as a preventative measure if clogging has
been a problem.

4.12 9926816 R06 - 2014-2016 RZR XP 1000 / XP4 1000 Service Manual
© Copyright Polaris Industries Inc.