Polaris A07MH46AA Offroad Vehicle User Manual


 
4.23
FUEL INJECTION
4
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 lines or fuel injectors restricted
Fuel filter plugged
Fuel pump inoperative
Air leak in system
Intake air leak (throttle shaft, intake boot, gasket or
grommet)
Throttle stop screw tampering - replace throttle body
Failed Sensor or disconnected wiring
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 duct)
Air filter dirty/plugged
Poor fuel quality (old fuel)
Fouled spark plug
TPS setting incorrect
Injector failure
Failed Sensor or disconnected wiring
Throttle stop screw tampering - replace throttle body
POOR IDLE
Symptom: Idle Too High (If greater than 1300 RPM when
engine is warm)
Throttle stop screw tampering - replace throttle body
Throttle cable sticking, improperly adjusted, routed
incorrectly
Failed Sensor or disconnected wiring
IAC stuck or inoperative
Intake air leak
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 - replace throttle body
Failed Sensor or disconnected wiring
Symptom: Erratic Idle
Throttle cable incorrectly adjusted
Air Leaks, dirty injector
TPS damaged or adjusted
Tight valves
Belt dragging
Dirty air cleaner
•Engine worn
Spark Plug fouled
Throttle stop screw tampering - replace throttle body
Failed Sensor or disconnected wiring
The correct position of the throttle body idle
stop is established and set at the factory. Do not
loosen the throttle body idle stop or alter the
stop position in any fashion. If the stop is
repositioned, the entire throttle body assembly
must be replaced.