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158 EMISSION CONTROLS AND FUEL SYSTEM
OPEN PRIMARY
THROTTLE VALVES
SO THAT FAST IDLE
CAM FOLLOWER
CLEARS FAST IDLE
CAM
Quadrajet
18
' front vacuum
break adjustment—
early models without an adjusting screw
©PUSH UP LIGHTLY ON
VACUUM BREAK LEVER
TO CLOSE CHOKE (HOLD
IN POSITION WITH
RUBBER BAND)
HOLD
PRIMARY
THROTTLE
VALVES WIDE
OPEN
BE~ND TANG ON
LEVER TO
ADJUST
Quadrajet®
unloader
adjustment—
1974 and ear' Her
models shown,
later models similar
CHOKE UNLOADER ADJUSTMENT
Close the choke valve and secure it with a
rubber band hooked to the vacuum break le-
ver. Open the primary throttles all the way.
Then measure the distance between the air
horn and edge of the choke butterfly. On
models up to and including 1976, use the
bottom side of the butterfly for this measure-
ment; on 1977 and later models, use the top
side. Bend the fast idle lever tang to achieve
the proper opening of the choke.
AIR VALVE SPRING ADJUSTMENT
NOTE:
Loosening and tightening the lock-
ing screw to adjust the air valve spring re-
WITH LOCK SCREW LOOSENED AND WITH
AIR VALVE CLOSED
,
TURN ADJUSTING
SCREW HALF TURN AFTE R SPRING
CONTACTS PIN
.
TIGHTEN IOCK
5
CBEW
_
" '
S P R I N G
Quadrajet® air valve spring adjustment
FIGURE 1.
SEAT DIAPHRAGM USING
VACUUM SOURCE
*-
NOTE: ON DELAY
MODELS WITH AIR BLEED,
REMOVE RUBBER COVER OVER
FILTER ELEMENT AND PLUG
SMALL BLEED HOLE IN VACUUM
TUBE WITH TAPE. ON MODELS
WITH AIR BLEED IN END COVER,
PLUG COVER WITH 1" MASKING
TAPE. REMOVE TAPE AFTER
ADJUSTMENT.
Quadrajet
81
front vacuum break adjustment—late models with an adjusting screw
GAUGE BETWEEN AIR HORN WALL
AND LOWER EDGE OF CHOKE VALVE
VACUUM
PLUNGER MUST
BE •ULLY SEATED
USE OUTSIDE
VACUUM SOURCE
LIGHTLY ROTATE CHOKE
COIL LEVER COUNTERCLOCK
WISE UNTIL END OF ROD IS
IN END OF SLOT IN LEVER
BEND ROD
TO ADJUST
'» GAUGE BETWEEN AIR HORN
WALL AND LOWER EDGE OF
"CHOKE VALVE
TENSION
ADJUSTING
SCREW
LEVELING
BUBBLE
'(CENTERED)
\
CHOKE
VALVE
CLOSED
SPECIFIED
ANGLE (SEE SPECS.)
DEGREE
SCALE
2) POINTER
MAGNET
TURN SCREW
TO ADJUST
UNTIL BUBBLE
IS CENTERED
NOTE: LEAF BUCKING
SPRING MUST BE
SEATED AGAINST
LEVER (WHERE
USED)
CLOSE CHOKE
BU PUSHING UPWARD
ON CHOKE COIL LEVER OR VACUUM
BREAK LEVER TANG (HOLD IN POSITION
WITH RUBBER BAND).
FIGURE 2