GMC 1976 ZEO 6083 Maintenance Manual page 380

6T- 10
EMISSION CONTROL SYSTEMS
FROM CARBURETOR VACUUM
VACUUM SWITCH
ADJUSTING SCREW
VENT FILTER
TO THROTTLE LEVER
ACTUATOR DIAPHRAGM
COVER
A-4638
3 . Adjustment should be made with engine cold,
and not running.
4. Apply 20 in . Hg . vacuum to the actuator .
Manually open the throttle to allow the choke to set
(top step on fast idle cam) . The choke will set only
if the engine is cold . If the engine is too warm and
choke won't set, it can be set by hand .
5 . Loosen stem nut. Adjust actuator by rotating
until plunger tip contacts throttle lever.
6. Tighten stem nut, remove vacuum pump and
complete hose connections .
Figure 13-Control Valve Adjustment
Figure 14-Throttle Actuator Adjustment