Toyota COMPUTER-CONTROLLED SYSTEM Training Manual page 129

OTHER CONTROL SYSTEMS - SCV Syste m
SCV (SWIRL CONTROL VALVE) SYSTE M
The intake port has been divided longitudinally
into two passages as shown in the following
illustration .
The swirl control valve, which is opened and
closed by the intake manifold vacuum, is
mounted in passage ;A .
Exhaust valve
Swirl control ~ Intake valv e
valve (closed)
®
When the engine is running under a light load or
below a certain rpm, this valve closes, creating a
powerful swirl . This increases combustion
efficiency, thereby improving fuel economy .
Under a heavy load or over a certain rpm, the
valve opens, increasing intake efficiency, and
thus improving engine output .
A swirl control valve is provided in the intake
port of each cylinder .
Swirl control lin k
Intake
po
rt
Passage B
Passage B
OHP 82
OHP 8 2
Thro
tt
le
position
sensor
Manifol d
pressur e
sensor valve
Swirl control valve
OHP 82
117