4.26
ELECTRONIC FUEL INJECTION
9924096 - 2013 RANGER RZR XP 900 / RZR XP 4 900 Service Manual
© Copyright 2012 Polaris Sales Inc.
Fuel Injector Troubleshooting
Injector problems typically fall into three general
categories- electrical, dirty / clogged, or leakage. An
electrical problem usually causes one or both of the
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.
If an injector is not operating, it can indicate either a bad
injector, or a wiring/electrical connection problem. Check
as follows:
Injector leakage is very unlikely, but in rare instances it can
be internal (past the tip of the valve needle), or external
(weeping around the injector body). The loss of system
pressure from the leakage can cause hot restart problems
and longer cranking times.
Injector problems due to dirt or clogging are unlikely due
to the design of the injectors, the high fuel pressure, the
use of filters and the detergent additives in the gasoline.
Symptoms that could be caused by dirty/clogged 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.
Fuel Injector Test
IMPORTANT: Take note of PTO and MAG fuel injector
harness connectors before disconnecting them. The
harness leads are marked with PTO and MAG
identifiers.
The fuel injectors are non-serviceable. If diagnosis
indicates a problem with either injector, test the resistance
of the fuel injector(s) by measuring between the two pin
terminals:
IMPORTANT: Be sure to connect the PTO harness
lead to the PTO injector and the MAG harness lead to
the MAG injector to ensure proper engine operation.
Fuel Injector Resistance Specification:
11.4
- 12.6
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