Fuel System Troubleshooting - Polaris RANGER XP 900 2018-2019 Service Manual

FUEL SYSTEM 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 line or fuel injectors restricted
• Fuel filter plugged
• Fuel pump inoperative
• Air leak in system
• Intake air leak (intake boots, intake adaptors, airbox
cover)
Rich Mixture
Symptoms: Fouls 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 boots)
• Air filter dirty/plugged
• Poor fuel quality (old fuel)
• Fouled spark plug
• Injector failure
9929399 R01 - 2018-2019 RANGER XP/ CREW 900/1000 Service Manual
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Poor Idle
Symptom: Idle Too High (if > 1400 RPM when warm).
• Electronic Throttle Control (ETC) tampering or damage
• Pedal Position Sensor (PPS) tampering or damage
• Faulty electrical connection
Symptom: Idle Too Low (if < 1100 RPM when warm).
• Electronic Throttle Control (ETC) tampering or damage
• Pedal Position Sensor (PPS) tampering or damage
• Plugged air filter
• Leaking injector (rich condition)
• Belt dragging
Symptom: Erratic Idle.
• Air Leaks, dirty injector
• ETC damaged (check with Digital Wrench®)
• PPS damaged (check with Digital Wrench®)
• Tight valves (low compression or high leakdown)
• Belt dragging
• Dirty air filter
• High percentage of cylinder leakdown (worn engine)
• Low compression (worn engine)
• Spark plug(s) fouled
• Spark plug wires loose or worn
• Faulty electrical connection
FUEL SYSTEM
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