Chevrolet 1977 light duty truck, Service Manual

Page: 535 / 861

IN T E R N A L V E N T
P R E S S U R E
R E LIEF V A L V E
Fig. 6C-3--Float System
T O P A IR BLEED
T U B E TO
E G R * vV A L V E
H O T ID LE
C O M P E N S A T O R
T H R O T T L E V A L V E
ID LE D IS C H A R G E H O LE
E G R (E X H A U S T G A S
R E C IR C U L A T IO N )
. ID LE C H A N N E L
R E S T R IC T IO N
- ID LE TU B E
_ M A IN M E T E R IN G J E T
T IM E D V A C U U M
POR TS FOR E.G .R .*
ID L E M IX T U R E NEEDLE
OFF— ID LE
O P E R A T IO N
Fig. 6C-4--ldle System
M A IN D IS C H A R G E -
N O Z Z L E
BO O ST V E N T U R I
M A IN V E N T U R I
M A IN W E L L A IR B L E E D
POW ER P IS TO N
M E T E R IN G R O D
POW ER P IS TO N
'S P R IN G
^ 3
T H R O T T L E V A L V E
,M A IN M E T E R IN G
„ C A L IB R A T IO N
SCREW
POW ER P IS TO N
A C T U A T IN G L IN K A G E
LOW ER ID L E A IR B L E E D
POW ER P IS T O N V A C U U M
Fig. 6C -5-M a in M ete rin g System
M A IN
D ISC H A R G E
NOZZLE
BOOST VE N TU R I
M A IN V E N TU R I
POWER PIS TO N
D R IV E ROD
^ M E T E R IN G
ROD
M A IN M E TE R IN G
JET
POWER PISTO N
A C T U A T IN G LIN K A G E
-P O W E R PISTON V A C U U M
LOW ER ID LE A IR BLEED
Fig. 6C-6--Power E nrichm ent System
" J "
D IS C H A R G E
S P R IN G R E T A IN E R
PUM P D IS C H A R G E
S P R IN G & B A L L
-P U M P L E V E R
P U M P P L U N G E R
D U R A T IO N
S P R IN G
P U M P R E T U R N
S P R IN G
P UM P A C T U A T IN G L IN K
P U M P CUP O P E R A T IO N