E.g.r. On Operation - Datsun 620 Series 1977 Service Manual

6
Thermal
vacuum
valve
Open
E G R
control
valve Close
E G R ON operation
The E
G
R circuit is completed
only when engine
coolant
temperature
Emission
Control
System
I
I
Note Vacuum condition
EC793
Fig
EC 51 E G R
not
actuated
is above the
working
temperature of
the
thermal
vacuum
valve and carbu
retor
suction
vacuum
is
large
enough
to
open
the E G R control valve
Y
m
l
fj
t1f
1t
3 0 l
P
@ 0
f Y f
1
i0
W g
1
i3
iiA
d
m
E
N
ti
n k
i
l
i
Throttle
valve
n
L
r
E G R control valve
Open
E G R control valva
The E G R control valve controls
the
quantity
of exhaust gas
to
be led
to the
intake manifold through vertical
movement
of
the
taper
valve connect
ed to the
diaphragm
to
which
vacuum
Thermal
vacuum
valve Open
Note
iiiI
Vacuum condition
EC794
Fig
EC 52 E G R actuated
is
applied
in response to
the
opening
of the carburetor throttle valve The
E G R control valve
is
installed
on
the
E G
R
passage
through
a
gasket
E G R
con
trol valve construction
and
type
vary with transmission
type
and
car
destination For identification
purposes
the
part
number is
stamped
on
the recessed
portion
at the
top
of
the valve
The
construction
of the E G R
control
valve is
shown below
EC
21