Chevrolet CHEVY VAN G10 SERIES Service Manual page 178

E NG INE FUEL 6M-4
( T )
DIAPHRAGM
PLUNGER MUST
BE SEATED.
USE OUTSIDE
VACUUM
V A C U U M BREAK ADJUSTMENT
Fig. 8C —V a c u u m B reak A d ju s tm e n t (M V )
4. W ith the choke valve held in this position, place specified
gauge betw een the low er edge o f the choke valve and air
h o rn wall.
5. D im ension should be as specified; if n o t, bend the
vacuum break rod at po in t show n, to adjust.
2GV (Fig. 8C)
8
Refer to Figure C and follow steps under MV.
4M V (Fig. 9C)
1. Seat choke vacuum
vacuum source.
2. O pen th ro ttle valve slightly so cam follow er will clear
steps o f fast idle cam. T hen rotate vacuum break lever
counterclockw ise (tow ards direction o f closed choke). A
rubber band m ay be used to hold in place. The end of
G A U G E BETW EEN A IR H O RN W A L L
A N D LOW ER EDGE OF CHO KE V A LV E
L IG H T L Y
C O IL LEVER C O U N T E R C LO C K ­
W IS E U N T IL END OF ROD IS
IN E N D OF SLO T IN LEVER
TO A D J U S T
VACUUM BREAK ADJUSTMENT
Fig. 9C —Vacuum Break A djustm ent (4 M V )
PLACE GAUGE BETWEEN UPPER
EDGE OF CHOKE V A L V E AND AIR
HORN W ALL
break diaphragm using outside
V A C U U M
P LU N G E R M U S T BE
FULLY S EA TE D
O U T S ID E
V A C U U M S O U RCE
OPEN P R IM A R Y THR O TTLE
V A L V E S SO T H A T FA ST IDLE
C A M FO LLO W ER CLEARS
F A S T IDLE C A M
Fig. 10C —U n lo a d e r A d ju s tm e n t (M V )
vacuum break rod shoul
vacuum break diaphragm plunger.
3. Measure the distance betw een lower edge o f choke valve
and inside air horn wall.
4. To adjust to specified dim ension, bend vacuum break
link at point shown.
CHOKE UNLOADER ADJUSTMENT
MV (Fig. 10C)
1. H old choke valve in closed position by applying a light
force to the choke operating lever.
2. R o tate th ro ttle lever to wide open th ro ttle valve position.
3. Bend unloader tang on th ro ttle lever to obtain specified
dim ension betw een lower edge o f choke plate (a t center)
and air horn wall.
2GV (Fig. 11C)
With the th ro ttle valves held wide open and the choke valve
held to w ard the closed position w ith a rubber band, bend the
unloader tang on the th ro ttle lever to obtain specified
clearance betw een the upper edge of the choke valve and air
horn wall.
CHOKE COIL ROD ADJUSTMENT
MV (Fig. 12C)
1. D isconnect therm ostatic coil rod from upper choke lever
and hold choke valve com pletely closed.
2. With therm ostatic coil rod disconnected, push dow nw ard
on rod to end o f travel.
3. W ith rod held in this position, the top o f rod should be
even w ith b o tto m o f hole in choke lever.
4. T o adjust, bend rod at point shown.
also be in outer end o f slot in
C H E V Y V A N SH O P M A N U A L