Pontiac tempest 1968 Service Manual page 315

6B-8 1968 P O N T I A C SERVICE MANUAL
d. Check idle mixture needle for burrs or
ridges.
e. If wear is noted on steps of fast idle cam,
it should be replaced as it may upset engine idle
during engine warm-up period.
f. Inspect pump plunger
0
Replace plunger if
synthetic rubber is scored, hardened or damaged.
g. Inspect for burrs on power piston or a
distorted power piston stem or spring.
4. Always use new gaskets in reassembly.
5. Clean all dirt or lint out of fuel inlet filter.
If filter remains plugged, replace it. Check relief
spring for distortion, replace it if necessary.
6. Thoroughly clean anti-bubble screen in main
well. If screen remains plugged, replace main well
support.
THROTTLE BODY ASSEMBLY
1. Install idle screw in throttle lever, if removed.
2. Screw idle mixture adjusting needle and spring
into throttle body until it is finger tight. Back
needle out five turns as a temporary idle mixture
adjustment.
3. Using new gasket, attach throttle body to bowl,
using two screws and lockwashers. Tighten screws
evenly and securely.
FLOAT BOWL ASSEMBLY
1. Install 3/16" steel ball into pump discharge
cavity. Carefully insert pump discharge spring and
guide on top of ball. Tap discharge guide lightly to
seat flush with float bowl casting.
NOTE: The pump discharge guide is installed
correctly when it is at right angles with pump
discharge jet.
2. Place pump return spring in pump well and
bottom spring in well by forcing downward with
index finger.
3. Install pump plunger assembly in bowl, making
sure not to curl rubber during installation.
4. Attach pump link to pump plunger rod and
throttle lever, using two hair pin clips.
NOTE: Dog leg in pump link will face away from
throttle shaft when installed correctly. Ends of
link will protrude outward away from throttle body.
AIR HORN ASSEMBLY
1. Install float needle seat and new gasket, using
special tool or screwdriver with 1/2" bit.
2. Place new air horn gasket on air horn, check
to be sure that all air horn and gasket holes are in
line.
3. Install power piston spring and power piston
in vacuum cavity.
NOTE: Piston should ride free in cavity.
4. Install power valve ball (small steel ball),
power valve spring, and retainer in main well sup­
port. Tighten retainer securely.
5. Attach main well support to air horn assembly
and tighten attaching screw securely.
NOTE: Check for free motion of power piston.
6. Install main metering jet in main well support.
7. Place float needle in float needle seat.
8. Place float carefully in position with drop tang
pointing downward towards air horn and install float
hinge pin.
FLOAT LEVEL ADJUSTMENT (Fig. 6B-15)
With air horn inverted and gasket in place, meas­
ure the distance from air horn gasket to bottom of
each float, as shown. Bend adjustment tang on float
arm which contacts float needle, as necessary, to
obtain specified dimension.
Align floats by making sure they are parallel and
centered in air horn gasket cut-out. Recheck float
level adjustment if float alignment is necessary.
GAUGE FROM GASKET
SURFACE TO TOP OF FLOAT
Fig. 6B-15 Float Level Adjustment