Fuel Injector Troubleshooting; Fuel Injector Test - Polaris ACE 900 2017 Service Manual

FUEL INJECTOR TROUBLESHOOTING

Injector problems typically fall into three general
categories- electrical, dirty / clogged, or leakage. An
electrical problem usually causes 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.
NOTICE
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. The fuel injector
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.
9929422 R02 - 2017-2019 ACE 900 Service Manual
© Copyright Polaris Industries Inc.

FUEL INJECTOR TEST

NOTE
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
q
the two pin terminals .
Fuel Injector Resistance Specification:
11.4 - 12.6 Ω
NOTE
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. The MAG wire
colors are Red/Blue and Black; the PTO wire colors are
Red/Blue and White.
FUEL SYSTEM
4
4.11