Choke Unloader Adjustment - Chevrolet 10 1971 Series Chassis Service Manual

SPECIFIED GAUGE
BETWEEN UPPER EDGE
OF CHOKE VALVE AND
AIR HORN CASTING
Fig. 5 C — Choke Rod (Fast Idle) Adjustment (2G V)
the closed position by turning the external choke lever
counterclockwise. Dimension between the lower edge of
choke valve, at choke lever end, should be as specified.
Bend choke rod to adjust (Fig. 5C).
CHOKE V A C U U M BREAK ADJUSTMENTS
(M V (Fig. 7C)
1. Remove air cleaner assembly from vehicle. On
vehicles with "Therm AC" air cleaner, plug the
sensor's vacuum take-off port.
2. Start engine or install a vacuum source such as
J-23309 to vacuum diaphragm vacuum tube.
3. Remove choke rod from choke lever and install a
rubber band to the lever in such a manner as to
react on the lever in a direction to close the choke
blade.
4. Slowly open accelerator until choke closes (choke
will not fully close due to the vacuum break link's
reaction on it) and idle is determined by high step of
fast idle cam. Release accelerator.
BEND TANG
TO ADJUST
FAST IDLE
SCREW ON
SECOND STEP
OF CAM
AGAINST
HIGH STEP
5. With idle determined by fast idle cam and vacuum
break link acting on the choke lever, insert specified
gauge (hold vertical) between the carburetor air horn
and choke blade.
6. Adjust vacuum break setting as necessary by bending
rod or tang as illustrated.
2GV (Fig. 8C)
Refer to Figure 8C and follow steps under MV.
4 M V (Fig. 9C)
Refer to Figure 9C and follow steps under MV.

CHOKE UNLOADER ADJUSTMENT

M V (Fig. IOC)
1. Hold choke valve in closed position by applying a
light force to the choke operating lever.
Fig. 7 C — Vacuum Break Adjustment (M V)
PLACE GAUGE BETWEEN UPPER
EDGE OF CHOKE VALVE AND
AIK HORN WALL
TO ADJUST
PUSH DIAPHRAGM
PLUNGER IN UNTIL
IT SEATS
VACUUM BREAK ADJUSTMENT
Fig. 8 C — Vacuum Break Adjustment (2 G V )
10-30 CHEVROLET TRUCK SERVICE MANUAL
ENGINE FUEL 6M-3