Gilera 633721 Workshop Manual page 278

Injection
THE TPS RESETTING PROCEDURE MUST NOT BE CARRIED OUT WITH A USED THROTTLE
BODY BECAUSE POSSIBLE VALVE WEAR AND STOP WEAR FOR THE MINIMUM OPENING
MAKE THE AIR FLOW DIFFERENTLY FROM THAT OF PRE-CALIBRATION.
Step motor
1
2
The throttle body is provided with an auxiliary air
circuit. This is enabled by a piston valve controlled
by a Stepper motor.
The Stepper is powered by the control unit only
when the opening must be changed.
The revolution is divided into portions called
"steps".
By changing the opening "steps" it is possible to
properly feed the engine to facilitate the start-up
procedure and adjust the air feeding with cold en-
gine. When the engine reaches the working tem-
perature, the Stepper partly closes again.
INJEC - 278
CIRCUIT LAYOUT
Specification
Electronic control unit
Stepper motor
Nexus 500 euro 3
Desc./Quantity
Stepper motor