Pontiac tempest 1968 Service Manual page 320

E N G I N E FUEL 6B-13
9. Remove power piston spring from power piston
cavity.
10. Remove power piston drive link from throttle
actuating lever by aligning Hp on rod and notch in
lever.
11. Remove actuating lever from accelerator pump
drive link in same manner. Note position of actuating
•lever for ease in reassembly.
12. Hold the pump plunger down in bowl cavity
and remove drive link from pump plunger shaft by
rotating link until Hp on link aligns with notch in
plunger shaft.
13. Remove pump plunger from float bowl.
14. Remove pump return spring from pump well.
15. Remove main metering jet from bottom of
float bowl.
16. Remove two screws from idle compensator
cover. Then remove cover, hot idle compensator
and seal from recess in bowl beneath compensator.
17. Idle screw and fast idle cam can be removed
at this time if desired.
No further disassembly of the float bowl Is
required.
THROTTLE BODY REMOVAL AND DISASSEMBLY
(Fig.
6B-29)
1. Invert carburetor bowl on bench and remove
two throttle body to bowl attaching screws. Throttle
body and insulator gasket may now be removed.
2. Remove idle mixture needle and spring.
NOTE: Due to the close tolerance fit of the throt­
tle valve in the bore of the throttle body, do not
remove the throttle valve or shaft.
CLEANING AND INSPECTION
The carburetor should be cleaned in a cold i m ­
mersion type cleaner.
1. Thoroughly clean carburetor castings and metal
parts in an approved carburetor cleaner such as
carbon-X (X-55) or its equivalent.
CA UTION: Any rubber parts, plastic parts, dia­
phragms, pump plungers, should not be immersed
in carburetor cleaner. However, the air horn
which has the plastic vent valve guide and cranking
enrichment valve will withstand normal cleaning in
carburetor cleaner. Make sure the cleaner is
thoroughly removed from choke enrichment valve
cavity.
2. Blow out all passages in castings with com­
pressed air. Do not pass drills through jets or
passages.
3. Inspect idle mixture needle for damage.
4. Examine float needle and seat assembly for
wear. Install a new factory matched set if worn.
5. Inspect upper and lower casting sealing sur­
faces for damage.
6. Inspect holes in levers for excessive wear or
out of round condition. If levers or rods are worn
they should be replaced.
7. Examine fast idle cam for excessive wear or
damage.
8. Check throttle and choke levers and valves for
binds and other damage.
9. Check all spring for distortion or loss in
tension, replace as necessary.
CARBURETOR ASSEMBLY AND
ADJUSTMENT PROCEDURES
THROTTLE BODY ASSEMBLY AND INSTALLATION
(Fig. 6B-29)
1. Install idle mixture needle and spring until
lightly seated. Back out five turns as a preHminary
idle adjustment.
2. Invert float bowl and install new throttle body
to bowl insulator gasket making sure all holes in
gasket align with holes in float bowl.
3. Install throttle body on bowl gasket so that all
holes in throttle body are aligned with holes in
gasket.
4. Install two throttle body to bowl attaching
screws. Tighten evenly and securely (12 - 15 lb. ft.)
Fig. 6B-29 Throttle Body Disassembly
OFF IDLE MIXTURE
PASSAGE
SPARK VACUUM PORT
CHOKE DIAPHRAGM VACUUM
:
, PASSAGE
IDLE NEEDLE
MIXTURE PASSAGE
OFF IDLE
DISCHARGE PORT
THROTTLE VALVI
IDLE MIXTURE
SCREW
IDLE COMPENSATOR
AIR CHANNEL
POWER PISTON VACUUM
VACUUM SOURCE ~
(DiVERTERVALVE)^
(DISTRIBUTOR SF&RK RETARD)