4.40
ELECTRONIC FUEL INJECTION
9924125 - 2013 RANGER RZR / RZR S / RZR 4 Service Manual
© Copyright 2012 Polaris Sales Inc.
EFI Troubleshooting
Fuel Starvation / Lean Mixture
Symptoms:
Hard start or no start, bog, backfire, popping
through intake / exhaust, hesitation, detonation, low
power, spark plug erosion, engine runs hot, surging, high
idle, idle speed erratic.
• No fuel in tank
• Restricted tank vent, or routed improperly
• Fuel lines or fuel injectors restricted
• Fuel filter plugged
• Fuel pump inoperative
• Air leak in system
• Intake air leak (throttle shaft, intake ducts, airbox
or a
ir cleaner cover)
• Incorrect throttle stop screw adjustment
Rich Mixture
Symptoms: Fo
uls spark plugs, black, sooty exhaust
smoke, rough idle, poor fuel economy, engine runs rough/
misses, poor performance, bog, engine loads up, backfire.
• Air intake restricted (inspect intake duct)
• Air filter dirty/plugged
• Poor fuel quality (old fuel)
• Fouled spark plug
• TPS setting incorrect
• Injector failure
Poor Idle
Symptom: Id
le Too High (If greater than 1300 RPM when
engine is warm).
• Throttle stop screw set incorrect
• Throttle cable sticking, impr
operly adjusted, routed
incorrectly
• Faulty electrical connection
Symptom:
Idle Too Low (if less than 900 RPM when
engine is warm).
• Plugged air filter
• Leaking injector (rich condition)
• Belt dragging
• Throttle stop screw tampering
Symptom: Erratic
Idle.
• Throttle cable incorrectly adjusted
• Air Leaks, dirty injector
• TPS damaged or adjusted
• Tight valves
• Ignition timing incorrect
• Belt dragging
• Dirty air cleaner
•Engine worn
• Spark Plug fouled
• Throttle stop screw set incorrectly (out of sync with
ECU)
• Faulty electrical connection