Choke Housing To Float Bowl - Pontiac TRANS AM 1977 Service Manual

FUEL SYSTEM 6C-47
1. Thoroughly clean all metal parts and blow dry with
compressed air. Make sure all fuel passages and metering
parts are free of burrs and dirt.
2. Check, repair or replace the following parts if the
following problems were encountered.
A. Flooding
1. Inspect float needle seat for dirt, deep wear grooves,
scores and proper seating.
2. Inspect float, float arms and hinge pin for distortion,
binds and burrs. Check float for leaks and/or being loaded
(heavier than normal).
B. Hesitation
1. Inspect pump plunger for cracks, scores or excessive
cup wear. A used pump cup will shrink when dry. Soak in
fuel for 8 hrs. before testing if dried out.
2. Inspect pump duration and return spring for being
weak or distorted.
3. Check for dirt in pump passages and jets, improper
seating of inlet or discharge balls, and scores in pump well.
4. Check pump linkage for excessive wear, repair or
replace as necessary.
C. Hard Starting
-
Poor Cold Operation
1. Check choke valve and linkage for excessive wear,
binds or distortion.
2. Inspect choke vacuum diaphragms for leaks.
3. Clean or replace carburetor filter.
4. Inspect inlet needle for sticking, dirt, etc.
5. Examine fast idle cam for wear or damage.
6. Also check items under "flooding".
D. Poor Performance
-
Poor Gas Mileage
1. Check power piston, and metering rods for dirt,
sticking, binding, damaged parts or excessive wear.
2. Clean all fuel and vacuum passages in castings.
E. Rough Idle
1. Inspect idle needle for ridges, burrs or being bent.
2. Inspect gasket mating surfaces on castings for damage
to sealing beads, nicks and other damage.
3. Clean all idle fuel passages.
4. Check throttle lever and valves for binds, nicks and
other damage.
CARBURETOR ASSEMBLY
Throttle Body
1. If removed, install idle mixture needles and springs
until seated. Back out the mixture needles three turns as a
preliminary idle adjustment. Final adjustment must be made
on the engine using the procedures described in idle mixture
adjustment procedure at the end of this section.
2. Install lower end of pump rod in throttle lever by
aligning tang on rod with slot in lever. End of rod should
point outwards towards throttle lever.
Float Bowl
NOTE: If a new float bowl assembly is used, stamp or
engrave the model number on the new float bowl. See
Fig. 6C-64).
1. Install new throttle body to bowl gasket over two
locating dowels on bowl.
2. Install throttle body making certain throttle body is
properly located over dowels on float bowl, then install
throttle body to bowl screws and lock washers and tighten
evenly and securely (Fig. 6C-84).
3. Place carburetor on proper holding fixtures such as
J 83281-1.
4. Install fuel inlet filter spring, filter and nut. Tighten
nut securely (18 ft. Ibs). (Fig. 6C-86).
C A U TI 0 N: Tightening beyond specified torque
can damage nylon gasket.
INLET N U 1
-FUEL FILTER
-
Fig. 66-86 Fuel Filter
Choke Housing To Float Bowl
1. Install new cup seal into plastic insert on side of float
bowl for intermediate choke shaft. Lip on cup seal faces
outward.
2. Install new cup seal into inside choke housing shaft
hole. Lips on seal faces inward, towards inside of housing.
3. Install fast idle cam onto the intermediate choke shaft
(steps on fast idle cam face downward).
4. Carefully install fast idle cam and intermediate choke
shaft assembly through seal in choke housing, then install
thermostatic coil lever onto flats on intermediate choke shaft.
The thermostatic choke coil lever is properly aligned when
both inside and outside levers face towards fuel inlet. Install
inside lever retaining screw into end of intermediate choke
shaft. Tighten securely.
5. Install lower choke rod inner lever into cavity in float
bowl. Install plastic tube seal into cavity on choke housing
before assembling choke housing to bowl. Install choke
housing to bowl sliding intermediate choke shaft into lower
choke inner lever.
NOTE: Tool J-23417 can be used to hold the lower
choke lever in correct position while installing the choke
housing (Fig. 6C-87).
6. Install choke housing retaining screw and washer and
tighten securely.
NOTE: The intermediate choke shaft lever and fast idle
cam are in correct position when the tang on lever is
beneath the fast idle cam. Do not install choke cover and