Chevrolet CHEVY VAN G10 SERIES Service Manual page 183

AU TO M A TIC CHOKE COIL ASSEMBLIES
Refer to " E xternal A djustm ents" for choke coil adjustm ent
procedures and typical installed views.
Choke Coil Replacement
In-Line Engines (Fig. K1)
N O T E : The following
IN -L IN E engines.
1. Rem ove air cleaner and disconnect choke rod upper clip.
2. Rem ove bolts attaching choke coil to m anifold, and
remove choke coil and choke rod as an assembly.
3. D isconnect choke rod from choke coil.
4. C onnect choke rod
assembly on m anifold.
5. Install bolts and tighten securely.
6
. A djust and connect choke ro d as outlined.
7. S tart and w arm -up the engine then check operation of
choke and install air cleaner.
V8 Engines (Fig. K2)
1. Remove air cleaner and disconnect choke rod upper clip.
2. Remove choke coil as follows:
WITH RO CHESTER 4MV AND 2GV CARBURETORS
Rem ove the choke coil shield by prying w ith a
screwdriver in the cut-out provided th e n lift shield
carefully over rod.
Rem ove choke rod, b rack et screw and choke coil
assembly.
3. Install a new choke coil assembly being sure the locator is
in th e hole o f the intake m anifold and install m ounting
screw.
4. Com plete installation as follows:
WITH RO CHESTER 4MV AND 2GV
CARBURETORS
Install the choke rod and adjust as necessary (w ith ­
o u t choke coil shield installed.)
D isconnect choke ro d u pper end and lower choke
coil shield over choke rod and install over choke coil.
5. Be sure choke valve moves freely from full open to full
closed position.
6
. S tart and w arm up the engine and check operation o f the
choke.
7. Install the air cleaner.
ON-THE-VEHICLE ADJUSTMENTS
Final curb idle an d fast idle settings should be m ade on the
vehicle using a tach om eter. All idle speeds in 1972 are to be
set w ith th e air conditioning in the O FF position unless
otherw ise indicated. Idle speed and m ixture settings m ust be
m ade w ith the air cleaner installed. Warm engine to norm al
operating tem perature, choke valve and therm ostatic air
cleaner valve m ust be in full open positions. Idle settings m ust
follow procedure show n on decal.
procedures refer to all
to new choke coil and install
A D D IT IO N A L EXTERN AL
SETTINGS A N D ADJUSTMENTS
ALL VEHICLES - EXCEPT VEGA
A fter carburetor overhaul, th ro ttle body p art replacem ent,
m ixture needle p a rt replacem ent, or lim iter cap and needle
rem oval, the below procedures m ust be follow ed:
1. Follow instructions on vehicle tune-up sticker (refer to
6
Section , T une Up) before proceeding.
2. T urn m ixture screw in un til it lightly contacts seat, th en
back screws o u t fo u r (4) full turns.
3. A djust idle stop solenoid to obtain, " initial curb idle
speed," see " O ther A djustm ents" Specifications chart in
back o f this section — Colum n No. 1.
4. T h e n a d ju s t m ix tu re screw s
to V4 tu rn rich fro m le an ro ll, w h en specified, to
o b ta in "fin al cu rb idle sp e ed ," see " O th e r A d ju s t­
m e n ts" S p ecificatio n s c h a rt in b ac k of th is S ectio n —
C o lu m n N o . 2.
5. In sta ll service "M ix tu re N eed le L im ite r C a p s " on
m ix tu re screw s.
6
. R e co n n e ct d istrib u to r v ac u u m hose a n d fu el ta n k
v a p o r hose.
IDLE STOP SOLENOID
(CURB ID L E -L O W IDLE) ADJUSTMENT
W ith engine a t n o rm a l o p e ra tin g te m p e ra tu re , a ir clea n er
in stalled , ch o k e o p en , a n d a ir c o n d itio n in g off, if so
e q u ip p ed .
C AU TIO N : Set p a rk in g b ra ke s a n d block the
d riv e w h eels.
1. D isco n n ect fu el ta n k h o se v a p o r can ister.
2. D isc o n n ec t d istrib u to r v ac u u m h o se a t th e d istrib u ­
to r. P lu g h o se le a d -to c a rb u re to r.
3. W ith engine ru n n in g .
ONE BARREL CARBURETORS
CAUTION: D u rin g a d ju s tm e n t, do n o t tu rn the
solenoid m ore th a n one co m plete tu rn w ith o u t
firs t disco n n e ctin g th e e le ctric a l w irin g .
a. T u rn th e so len o id clo ck w ise to in c re ase R P M ,
co u n terclo ck w ise to d ec rease R P M .
S p ecifications, S ectio n
ju stm e n ts", co lu m n N o. 2, fo r c u rb idle speed
(Id le S top S o len o id -E n erg iz ed ).
b. Set low idle sp eed (w ith so len o id d e-e n erg ize d )
to 4 5 0 R P M by u sin g an alien h ea d w ren ch
(lo c a te d a t th e en d of th is so le n o id ). T u rn to
ad ju st.
TW O BARREL A N D FOUR BARREL
CARBURETORS
a. D isco n n ect elec trica l co n n e ctio n a t th e en d of
th e idle sto p so lenoid.
b. A d ju st c a rb u re to rs low idle (A d ju s tm e n t screw
o n low step o f c a m ) to S p ecificatio n s in C o lu m n
N o. 2, N o te ( 3 ) .
ENG IN E FUEL 6M-9
eq u ally in (L e a n e r) o r
R e fe r to
6
M , u n d e r "O th e r A d ­
C H E V Y V A N S H O P M A N U A L