VESPA 946 E4 EMEA 2021 Manual page 198

Injection
Possible Cause
Exhaust system sealing (infiltrations)
Engine revs irregularly
ENGINE IRREGULAR PERFORMANCE WITH VALVE SLIGHTLY OPEN
Possible Cause
Intake system cleaning
Intake system sealing
Ignition system
Parameter reliability
TPS reset successful
Faults detected by self-diagnosis
Poor performance at full throttle
POOR ENGINE PERFORMANCE AT FULL POWER/ ENGINE IRREGULAR PERFORM-
Possible Cause
Faults detected by self-diagnosis
Power to spark plug
Intake system
Parameter reliability
Fuel system
INJEC - 198
Vespa 946 E4-E5 EMEA-USA-ASIA (2021-)
ANCE ON PICKUP
Operation
Manifold - head
Manifold - silencer
silencer welding
Operation
Air filter
Diffuser and throttle valve
Additional air pipe and Stepper
Intake sleeve
Filter housing
Spark plug wear check
Throttle valve position signal
Engine temperature signal
Intake air temperature signal
Ignition advance
TPS reset successful
Pump relay
H.V. coil
Injector
Engine speed timing sensor
Air temperature
Engine temperature
Lambda probe
Operation
Pump relay
H.V. coil
Injector
Engine speed timing sensor
Air temperature
Engine temperature
Lambda probe
Spark plug
Shielded cap
H.V. cable
H.V. coil
Air filter
Filter box (sealing)
Intake sleeve (sealing)
Throttle valve position signal
Engine temperature signal
Intake air temperature signal
Ignition advance
Fuel level in the tank
Fuel pressure
Fuel filter
Injector flow