VESPA 946 E4 EMEA 2021 Manual page 197

Vespa 946 E4-E5 EMEA-USA-ASIA (2021-)
Possible Cause
Correctness of the parameters
Intake system cleaning
Intake system sealing (infiltrations)
Fuel system (low pressure)
Engine does not rev down
ENGINE DOES NOT RETURN TO IDLING SPEED/IDLING SPEED TOO HIGH
Possible Cause
Faults detected by self-diagnosis
Ignition efficiency
Correctness of the parameters
Intake system sealing (infiltrations)
Fuel system (low pressure)
Exhaust backfires in deceleration
EXHAUST BACKFIRING WHEN DECELERATING
Possible Cause
Faults detected by self-diagnosis
Correctness of the parameters
Intake system sealing (infiltrations)
Fuel system (low pressure)
Operation
Throttle valve position sensor
Stepper
Engine temperature sensor
Intake air temperature sensor
Air filter
Diffuser and throttle valve
Additional air pipe and Stepper
Intake manifold - head
Throttle body - manifold
Intake sleeve
Filter housing
Fuel pump
Pressure regulator
Fuel filter
Injector flow
Operation
Pump relay
H.V. coil
Injector
Engine speed timing sensor
Air temperature
Engine temperature
Ignition timing
Throttle valve position sensor
Stepper
Engine temperature sensor
Intake air temperature sensor
Intake manifold - head
Throttle body - manifold
Intake sleeve
Filter housing
Fuel pump
Pressure regulator
Fuel filter
Injector flow
Operation
Pump relay
H.V. coil
Injector
Engine speed timing sensor
Air temperature
Engine temperature
Lambda probe
Throttle valve position sensor
Stepper
Engine temperature sensor
Intake air temperature sensor
Intake manifold - head
Throttle body - manifold
Intake sleeve
Filter housing
Fuel pump
Pressure regulator
Fuel filter
Injector flow
Injection
INJEC - 197