Air Horn Assembly And Installation; Fast Idle Adjustment (On Car); Idle Vent Adjustment - Pontiac Grand Prix Service Manual

ENGINE FUEL
6B-11
e. Use specified gauge
(.085)
and insert between bowl
casting sealing bead (gasket removed) and lower
surface of meterkg rod holder. Gauge should have a
slide fit between both surfaces, as shown.
f. To adjust, carefully bend metering rod holder up or
down at point shown.
g. After adjustment, install metering rod and tension
spring.
19. Install air horn gasket on float bowl by carefully
sliding slit portion of gasket over metering rod holder.
Then align gasket with dowels provided on top of bowl
casting and press gasket firmly in place.
AIR HORN ASSEMBLY AND INSTALLATION (Fig.
1. Install idle vent valve, if removed.
2. Install choke shaft, choke valve and vacuum break
lever, if removed. Align choke valve, tighten two
retaining screws and stake securely.
3. Install vacuum break diaphragm and plunger into
cavity at side of air horn. With choke valve in the open
position, slide eyelit of plunger rod over end of
vacuum break lever on choke valve.
4. Seat vacuum break diaphragm over sealing bead. on
air horn casting. With diaphragm held in place,
carefully install diaphragm cover and two retaining
screws. Tighten screws securely.
5. Install air horn to float bowl by lowering gently on
to float bowl until seated. Install three long and three
short air horn-to-float bowl attaching screws and
tighten securely
.
6. Assemble choke rod to the choke shaft lever. End of
rod points away from air horn casting when installed
properly.
7. Install lower end of choke rod into fast idle cam.
Steps on fast idle cam should face fast idle tang on
throttle lever.
8. Install upper choke lever to choke shaft. End of lever
faces towards vacuum break diaphragm. (See Fig.
6B-13) Install choke lever screw. Tighten securely.
IDLE VENT ADJUSTMENT (Fig. 68.21)
Set engine idle rpm to specification (solenoid inactive)
and hold choke valve wide open so that the fast idle
cam follower is not hitting the fast idle cam. Initial idle
setting can be made by turning idle screw in 1 1/2
turns
from closed throttle position.
With throttle lever held agihst the idle screw, the idle
vent valve should be open as swced. To measure,
GAUGE BETWEEN
BOTTOM OF VALVE
AH) TOP OF AIR
CAM FOLLOWER
OFF STEPS OF CAM
Fig. 6B-21. ldle Vent Adjustment
'
insert plug gauge between top of air horn casting and
bottom of vent valve.
To adjust, turn slotted vent valve head with screw-
driver, clockwise (inward) to decrease clearance and
counterclockwise (outward) to increase clearance as
needed.
FAST IDLE ADJUSTMENT (ON CAR) Fig. 68-22
1. Set normal engine idle speed. (Initial idle speed
setting off car is 1 1/2 turns in on idle speed screw
from closed throttle valve position).
2. Place fast idle cam follower tang on highest step of
cam.
3. To adjust insert end of screwdriver in slot provided
in fast idle cam follower tang and bend inward
(towards cam) or outward (away from cam) to obtain
specdied fast idle speed.
Fig. 6B-22 Fast ldle Adjustment