Chevrolet 1977 light duty truck, Service Manual

Page: 544 / 861

“2G ” TYPE
_ L
L.<
S H I F T I D E N T .
------- A S S E M . P L A N T C O D E
Y E A R
D A Y O F Y E A R
Fig. 16- Model 2GC C a rbu re to r Id e ntifica tio n
IDLE R ESTR IC TIO N ---------------^ I----------------- • E.G.R (E X H A U S T GAS
IDLE PASSAGE ^ R E C IR C U L A T IO N I
I D L E T U B E i \ IDLE AIR
\ -■ BLEEDS
MAIN WELL IN SER T^_ ^ T j
M A IN I -■■E.G.R. VALVE & SPARK
M E T E R IN G ---------------
\
S '
III
■ T IM E D
J
TIM ED V ACUUM
JETS 1 C A N ISTER ----- \ ^ PORT.
PURGE
T IM E D SPARK TUBE-;--------- H ( /
E G R -------- n
R E S T R I C T I O N '^ ^ L _ ^ J S f f l ^ j ,¥^ 3 ^ ^ I &
IDLE N E E D L E - (
o
FF ID L E /
pu^seTER idle ' 0FF IDLE\
TUBE D ISC H A R G E D IS C H A R G E THROTTLE
HOLE PORTS VALVE
Fig. 6C-19 -Idle System -California
F U E L IN L E T
F IT T IN G
F IL T E R
R ELIEF
F IL T E R S P R IN G
L A R G E IN T E R N A L
B O W L V E N T H O LE
P U L L -O V E R
E N R IC H M E N T
FUEL FEED
FUEL PIC K U I
TUBE —
M A IN NOZZLE
M A IN METERING
JET ---------------------
PART THROTTLE
A D JU S T M E N T SCREW
M A IN WELL
Fig. 6C-17 -Float System
Fig. 6C-20--Main M etering System
• E G R (E X H A U S T GAS
R E C IR C U L A T IO N )
IDLE R ESTR IC TIO N
IDLE PASSAGE^
IDLE TUBE
/
OFF IDLE
DISC H A R G E
PORTS
ID LE NEEDLE
IDLE
DISC H A R G E
HOLE THROTTLE
VALVE
M A N I F O L D V A C U U M
P O W E R
R E S T R I C T I O N S
M A I N W E L L