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138 EMISSION CONTROLS AND FUEL SYSTEM
FUEL TANK
^
PURGE AIR Schematic of the
evaporative emissions system (open)—1980; most models similar
Transmission Controlled Spark
(TCS)
Introduced in 1970, this system controls ex-
haust emissions by eliminating vacuum ad-
vance in the lower forward gears.
1970
The 1970 system consists of a transmission
switch, solenoid vacuum switch, time delay
relay, and a thermostatic water temperature
switch. The solenoid vacuum switch is ener-
gized in the lower gears via the transmission
switch and closes off distributor vacuum. The
two-way transmission switch is activated by
the shifter shaft on manual transmissions, and
by oil pressure on automatic transmissions.
The switch deenergizes the solenoid in high
gear, the plunger extends and uncovers the
vacuum port, and the distributor receives full
vacuum. The temperature switch overrides
the system when engine temperature is be-
low 63° or above 232°. This allows vacuum
advance in all gears. A time delay relay opens
15 seconds after the ignition is switched on.
Full vacuum advance during this delay elim-
inates the possibility of stalling.
DISTRIBUTOR ASSEMBLY
CLEAN AIR VENT
^ S O L E N O I D
(VALVE IN HIGH
GEAR POSITION)
MANIFOLD
CARBURETOR
TRANSMISSION SWITCH
_L
—
TVi
RELAY
(CLOSED EXCEPT WHEN TEMPERATURE
,_ OVERRIDE SWITCH IS CLOSED)
1
1970 TCS system
schematic
FUSE
IGNITION
TH
i
THERMOSTATIC
TEMPERATURE OVERRIDE
SWITCH
CARBURETOR
VACUUM SIGNAL
OFF IDLE PURGE
PORT
BOWL VENT
IDLE PURGE LINE
IDLE PURGE PORT
(CONSTANT)
PRESSURE-VACUUM
RELIEF GAS CAP
VAPOR STORAGE
CANISTER
VACUUM ADVANCE UNIT
COLD
VACUUM
Содержание 1963 Corvette
Страница 29: ...3 0 1973 3 0 15 18 Is 454 8 18 24 15 4 0...
Страница 36: ...GENERAL INFORMATION AND MAINTENANCE 31 CM E 8 in 1 o s 1 O 1 8 o o o o CD o o o CO E o o o co JD in fCD I ts...
Страница 83: ...OHMMETER OHMMETER Stator testing perforated case models...
Страница 125: ...Wear ridge must be removed before piston removal...
Страница 161: ...14 Vacuum piston 15 Vacuum piston spring 16 Pump plunger assembly 17 Pump plunger return spring 18 Primary float...
Страница 205: ...EMISSION CONTROLS AND FUEL SYSTEM 187 8 CO 8 8 8 8 inCM CO 8 CM I I I IS N ino 1...