Chevrolet CHEVY VAN G10 SERIES Service Manual page 177

HOLD DOWN ON
CHOKE VALVE
CHOKE ROD (FAST IDLE C A M ) A D JUSTM ENT
Fig. 4 C —Choke Rod (Fast Idle Cam) A djustm ent (M V )
M anual choke m odels w ith sm ooth co n to u r cam. Use the
same procedure as above except for S tep 1.
As there are no steps on m anual choke cam , the index line
on side o f cam should be lined up w ith con tact p o in t o f the
fast idle cam follow er tang.
2GV (Fig. 5C)
T urn stop screw in un til it ju st contacts b o tto m step o f fast
idle cam. Then tu rn screw in one full tu rn . Place idle screw on
second step o f fast idle cam against shoulder o f high step. With
screw in this po sition, hold choke valve tow ard closed position
w ith a rubber b and and check clearance betw een upper edge of
choke valve and air horn wall. A djust to specified dim ension
by bending tang on choke lever and collar assembly.
4M V (Fig. 6C)
With the cam follow er on second step o f fast idle cam and
against the high step, ro tate the choke valve tow ard the closed
Fig. 5C—Choke Rod (Fast Idle Cam) A djustm ent (2 G V )
ROD IN END
OF SLOT
GAUGE BETW EEN CHOKE
VALVE AND A IR HORN W ALL
BEND ROD TO ADJU ST
CAM FO LLO W ER MUST BE
HELD FIRM LY ON SECOND
S TE P OF FAST ID LE CAM
AGAIN ST HIGH STEP
position by turning the external choke lever counterclockw ise.
D im ension betw een the low er edge o f choke valve, at choke
lever end, should be as specified. Bend choke rod to adjust
6
(Fig. C).
CHOKE VACUUM BREAK ADJUSTMENTS
(MV) (Fig. 7C)
The following procedure for adjusting the vacuum break
diaphragm unit is used to insure correct initial choke valve
opening after engine starting:
1. Remove air cleaner assembly from vehicle. On vehicles
w ith " T herm AC" air cleaner, plug the sensor's vacuum
take-off p o rt.
2. Using an outside vacuum source, apply vacuum to the
vacuum break diaphragm until the plunger is fully seated.
3. With the vacuum b reak diaphragm in th e fully seated
position, push the choke valve tow ard the
position.
Fig. 7C —Vacuum Break A djustm ent (M V )
ENG INE FUEL 6M-3
closed
C H E V Y V A N SH O P M A N U A L