Pontiac tempest 1968 Service Manual page 323

6B-16
1968 P O N T I A C SERVICE MANUAL
Fig. 6B-34 Fast Idle Adjustment
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 (Fig. 6B-34)
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. With tang held against cam check clearance
between end of slow idle screw and idle stop tang on
throttle lever. It should be as specified; (.090").
4. To adjust insert end of screw driver in slot
provided in fast idle cam follower tang and bend
inward (towards cam) or outward (away from cam)
to obtain specified dimension.
CHOKE ROD ADJUSTMENT
With fast idle adjustment made (Fig. 6B-35)
1. Place fast idle cam follower on second step of
the fast idle cam and hold firmly against the rise
to the high step.
2. Rotate choke valve towards direction of closed
choke by applying force to choke coil lever.
3. Bend choke rod at point shown to give specified
opening between the lower edge of choke valve (at
center of valve) and inside air horn wall.
GAUGE B E T W E E N CHOKE VAIVE AND AIR HORN WALL
Fig. 6B-35 Choke Rod Adjustment
VACUUM BREAK ADJUSTMENT (Fig. 6B-36)
1. Open throttle valve so that cam follower on
throttle lever will clear highest step on fast idle
cam,
2. Rotate choke valve to closed position. If
thermostatic coil is warm, hold choke valve closed
with rubber band or spring attached between choke
shaft lever and stationary part of carburetor.
3. Grasp vacuum break plunger rod with needle
nose pliers and push straight inward until dia­
phragm seats.
4. With specified plug gauge, measure clearance
between lower edge of choke valve and inside air
horn wall at center of valve as shown.
5. Bend end of vacuum break lever at point shown
to adjust.
BEND TANG TO ADJUST GAUGE BETWEEN LOWER
Fig. 6B-36 Vacuum Break Adjustment