Chevrolet CAMARO 1979 Service Manual page 564

6C.12 FUEL SYSTEM
M O D E L l M E C A R B U R E T O R
G E N E R A L D E S C R I P T I O N
The Monojet, carburetor (Fig. 6C1-1i) is a single bore
downdraft carburetor using a tripie venture in conjunction
with a plain tube nozzle.
Fuel flow through the main metering system $
controlled by a main well air bleed ând a variable olifiæjet.
A power enrichmeflt system is used to provide good
pe{ormânce during moderate to heavy âcceleration and at
higher engiûe speeds.
The idle system incorporâtes a hot idle compensator
to maintain smooth €ngine idle during periods of extreme
hot engine operation.
The model IME incorporates atr int€grâl âutomatic
choke system which ùses ân electrically heâted choke coil.
Th€ vacuum diâphragm unit is mounted externally on the
air horn aûd connects to the choke lever through th€
vacuum bæak link.
The electric choke coil is contâined in a choke housing
mounted on a bracket attached to the float bowl.
An integral, pleated-paper fuel inlet filter ls mount€d
rn the fuel bowl behind lhe fuel inler nut to give mâximum
filtraton ofincoming fuel. A check vâlve is us€d in the filter
inlet to prevent fùel drâining from the fuel system âfter roll-
Other features of the Monojei cârburetor include ân
aluminum throttle body for decrcâsed w€ight and inprov€d
heat distribuaion and â thick throttle body to bowl insulâtor
gasket to keep exc€ssive engine heat from the float bowl
venting of fuel vapors from the carburetor float bowl is
accomplished by a hose conneciing a tube in the air horn
to a vapor canister.
The carbùretor model identification is stâmped on â
vertical portion of the float bowl, âdjacent to the fùel inlet
nùt (Fie.6C1-12).
If replacing the float bowl, follow the manufacturer\
instructions contained in the service package so thât the
identification number can be transferr€d to the new float
An electrically operated idle stop solenoid is used on
â11 modeis.
Dual throttle retun spings âreused on ali carburetors.
The throttle lever has a spun-in plastic bushing, this
is us€d âs the beâring surface for the dual thrcttle return
sprinss.
NOTICE: The spun-in plâstic return spdng bushitg
will withstând normal cleâning time in âû approved
cold irnmersion type carburetor cleâner' The bushing
is not s€rviced separately ând should not b€ removed
from the carburetor throttl€ lever-
An Exhaust Gas Recirculâtion system (EGR) is used
on all applications to control oxides of nitrogen. The
vâcuum supply port necessâry to operât€ the recirc! âtion
valve is located in th€ throttle body and connects through
â channel to a tube which is locat€d at the top of the air
homcâsting. SeeIdleSystem(Fig
6C1'14)forPortlocation
Sixbâsicsystems ofoperâtion are used:float, idle, main
metering, poiver enrichment, pump and choke Fig 6Cl-13
throùgh 19.
I
F i 9 6 C 1 . 2 1 , 4 o o e l M E C d ' b J ' e r o ' o e ' I i c " r o l
F i g 6 c l . l 1 M o d e 1 N 4 E C a r b u r e t ô r