Sentra L4-1.8L (QG18DE) (2004)
Variable Induction Control Valve: Description and Operation
SWIRL CONTROL VALVE
Component Description
Swirl control valve consists of actuator and valve. The valve is installed in the intake manifold, and the actuator is connected to the rear end of the valve
shaft.
The swirl control valve uses a step motor which has four winding phases. It operates according to the output pulse signal of the ECM. Two windings are
turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes. When no change in the control position is needed, the ECM
does not issue the pulse signal. A certain voltage signal is issued so that the valve remains at that particular opening.
SWIRL CONTROL VALVE
Description
System Description
SYSTEM DESCRIPTION
Swirl control valve has a valve portion in the intake passage of each cylinder.
While idling and during low engine coolant temperature, the swirl control valve closes, Thus the velocity of the air in the intake passage increases,
promoting the vaporization of the fuel and producing a swirl in the combustion chamber.
Because of this operation, this system tends to increase the burning speed of the gas mixture, improve fuel consumption, and increase the stability in
running conditions.
Also, except when idling and during low engine coolant temperature, this system opens the swirl control valve. In this condition, this system tends to
increase power by improving intake efficiency via reduction of intake flow resistance, intake flow.
The swirl control valve is operated by the ECM.