Page 198 - Manual Oficina Polaris RZR 570 13-18

FUEL SYSTEM

FUEL INJECTORS

OPERATION OVERVIEW FUEL INJECTOR TROUBLESHOOTING
The fuel injector is mounted into the cylinder head, with Injector problems typically fall into three general
the fuel rail retaining it from the top end. O-rings on both categories- electrical, dirty / clogged, or leakage. An
ends of the injector prevent external fuel leaks and also electrical problem usually causes one or both of the
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.
CAUTION
Do not apply voltage directly to the fuel injector.
Excessive voltage will burn out the injector. Do not
ground the injector 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. If an injector is not operating, it can indicate either a bad
During engine operation, the ECU completes the ground injector, or a wiring/electrical connection problem. Check
circuit, energizing the injectors. The valve needle in each as follows:
injector is opened electromagnetically, and the pressure Injector leakage is very unlikely, but in rare instances it
in the fuel rail forces fuel down through the inside. The can be internal (past the tip of the valve needle), or
“director plate” at the tip of the injector contains a series external (weeping around the injector body). The loss of
of calibrated openings which directs the fuel into the system pressure from the leakage can cause hot restart
intake port in a cone-shaped spray pattern. problems and longer cranking times.
The amount of fuel injected is controlled by the ECU and Injector problems due to dirt or clogging are unlikely due
determined by the length of time the valve needle is held to the design of the injectors, the high fuel pressure, the
open, also referred to as the “injection duration” or “pulse use of filters and the detergent additives in the gasoline.
width”. It may vary in length depending on the speed and Symptoms that could be caused by dirty/clogged
load requirements of the engine. injectors include rough idle, hesitation/stumble during
acceleration, or triggering of fault codes related to fuel
delivery. Injector clogging is usually caused by a buildup
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 9926813 R06 - 2013-2016 RZR 570 Service Manual
© Copyright Polaris Industries Inc.