Chevrolet Corvette 1963 Repair & Tune-Up Manual page 145

REMOVAL AND INSTALLATION
Vacuum Motor
1. Remove the air cleaner.
2. Disconnect the vacuum hose from the
motor.
3. Drill out the spot welds with a Vs" hole,
then enlarge as necessary to remove the re
taining strap.
4. Remove the retaining strap.
5. Lift up the motor and cock it to one side
to unhook the motor linkage at the control
damper assembly.
Install the new vacuum motor as follows:
7
6. Drill a /64" hole in the snorkel tube as
the center of the vacuum motor retaining
strap.
7. Insert the vacuum motor linkage into the
control damper assembly.
8. Use the motor retaining strap and a
sheet metal screw to secure the retaining strap
and motor to the snorkel tube.
NOTE: Make sure the screw does not inter-
fere with the operation of the damper as-
sembly. Shorten the screw if necessary.
Temperature Sensor
1. Remove the air cleaner.
2. Disconnect the hoses at the air cleaner.
3. Pry up the tabs on the sensor retaining
clip and remove the clip and sensor from the
air cleaner.
4. Installation is the reverse of removal.
Evaporative Emission Control
(EEC)
1970-1981
Introduced on California cars in 1970, and
nationwide in 1971, this system reduces the
amount of escaping gasoline vapors. Float
bowl emissions are controlled by internal car-
buretor modifications. Redesigned bowl
vents, reduced bowl capacity, heat shields,
and improved intake manifold-to-carburetor
insulation serve to reduce vapor loss into the
atmosphere. The venting of fuel tank vapors
into the air has been stopped. Fuel vapors
are now directed through fines to a canister
containing an activated charcoal filter. Un-
burned vapors are trapped here until the en-
gine is started. When the engine is running,
the canister is purged by air drawn in by
manifold vacuum. The air and fuel vapors are
then directed into the engine to be burned.
This system is designed to reduce fuel vapor
EMISSION CONTROLS AND FUEL SYSTEM
emission. The canister filter should be re-
placed every 12 months or 12,000 miles on
Models 1970-74, on Models 1975-81 the in-
terval was extended to 24 months or 30,000
miles. To replace the filter, proceed as fol-
lows:
canister. Pull out the old filter and work the
new filter into place. It may be necessary to
remove the bottom of the canister for ac-
cess.
1982-84
The EEC system for 1982 and later performs
the same function as the earlier system, but
uses a purge control solenoid which is in-
stalled in the vacuum line between the char-
coal canister and the PCV valve (mounted on
the driver's-side fender, under the hood). The
ECM of the computerized emissions system
controls the action of the purge control sole-
noid. Depending upon various conditions of
operation, the ECM will either energize or
de-energize the solenoid. When the solenoid
is energized, vacuum is not available to draw
fuel vapors from the canister; when de-ener-
gized, vacuum draws the canister vapors into
the intake tract of the engine. The solenoid is
mounted on the drivers-side fender, inside
the engine compartment. Replacement of the
solenoid is simply a matter of tagging/
disconnecting the hoses and wiring from the
solenoid, and unbolting the solenoid.
Anti-Dieseling Solenoid
Some 1968—76 models may have an idle speed
solenoid on the carburetor. All 1972—74
models have idle solenoids. Due to the leaner
carburetor settings required for emission
control, the engine may have a tendency to
"diesel" or "run-on" after the ignition is
turned off. The carburetor solenoid, ener-
gized when the ignition is on, maintains the
normal idle speed. When the ignition is
turned off, the solenoid is de-energized and
permits the throttle valves to fully close, thus
preventing run-on.
is NOT an anti-dieseling solenoid; on these
models, the solenoid is used to increase the
idle speed when the air conditioning com-
pressor is engaged.
lenoids see Carburetor Adjustments.
The filter is located in the bottom of the
The solenoid used on most 1977-81 models
For adjustment of carburetors with idle so-
137