SECTION 6M
ENGINE FUEL
CONTENTS OF THIS SECTION
Page
Carburetors 6M-1 Fuel Pumps .
Air Cleaners 6M-7 Special Tools
Page
6M-10
6M-12
CARBURETORS
INDEX
Page
General Description 6M-1
Service Procedures 6M-1
Preliminary Checks 6M-1
Idle Speed and Mixture Adjustment ........... 6M-1
Fast Idle Adjustment .................. 6M-3
Choke Adjustment 6M-3
Float Adjustment 6M-4
Page
Additional Adjustments 6M-4
Removal 6M-4
Test Before Installation 6M-5
Installation 6M-5
Fuel Filter Maintenance 6M-5
Choke Coil Replacement 6M-5
Throttle Linkage Adjustment . . 6M-6
GENERAL DESCRIPTION
Various carburetors (fig. lc) are used with Chevrolet,
Chevelle, Chevy II, Camaro and Corvette passenger
vehicles. These carburetors are designed to meet the
particular requirements of engines, transmissions and
vehicles, therefore carburetors that look alike are not
always interchangeable. (Refer to carburetor part num-
ber and/or specifications.)
Because many service procedures for the various
carburetors are similar, typical illustrations and pro-
cedures are used except where specific illustrations or
procedures are necessary to clarify the operation.
This section covers removal, installation and adjust-
ments (on engine) of carburetors. Also covered in this
section are maintenance procedures for choke coils,
throttle linkage and fuel filters. For carburetor .over-
haul procedures and additional adjustments (bench), re-
fer to Section 6M of the Overhaul Manual under the
carburetor being serviced.
Specifications for carburetors are located in the back
of this manual.
SERVICE PROCEDURES
Preliminary Checks
1.
Thoroughly warm-up engine. If the engine is cold,
allow to run for at least 15 minutes.
2.
Inspect torque of carburetor to intake manifold bolts
and intake manifold to cylinder head bolts to exclude
the possibility of air leaks.
3.
Inspect manifold heat control valve (if used) for free-
dom of action and correct spring tension.
Idle Speed and Mixture Adjustment (Except Air Injection
Reactor System)
NOTE:
This adjustment should be performed
with engine at operating temperature and park-
ing brake applied.
1.
Remove Air Cleaner.
2.
Connect tachometer and vacuum gauge to engine, then
set hand brake and shift transmission into neutral.
3.
As a preliminary adjustment, turn idle mixture
screws lightly to seat and back out 1-1/2 turns.
CAUTION: Do not turn idle mixture screw
tightly against seat or damage may result.
4.
With engine running (choke wide open) adjust idle
speed screw to specified idle speed, (automatic
transmission in drive, synchronized transmission in
neutral).
5. Adjust idle mixture screw to obtain highest steady
vacuum at specified idle speed.
NOTE:
On air conditioned vehicles, turn air
conditioning to the "on" position and hold the
hot idle compensator valve closed while adjust-
ing idle speed and idle mixture screws.
NOTE:
On Rochester BV carburetors the idle
mixture screw should be turned out 1/4 turn
from the "lean roll" position. The definition
of "lean roll" point is a 20 to 30 rpm drop
in engine speed obtained by leaning the idle
mixture.
6. Repeat Steps 4 and5 as needed for final adjustment.
NOTE:
If necessary, final adjustment of the \
carburetor may be made with the air cleaner
installed.
7. Turn engine off, remove gauges and install air
clearer.
CHEVROLET CHASSIS SERVICE MANUAL
AIR INJECTOR REACTOR SYSTEM
6T-2
AIR
MANIFOLD
MIXTURE
CONTROL
VALVE
AIR
INJECTION
PUMP
IN LINE
MIXTURE
CONTROL
VALVE
AIR INJECTION
PUMP
CHECK
VALVE
V8
Fig.
I—Air
Injection Reactor System (Typical)
• Install
and
adjust drive belt
as
outlined above.
• Hold pump pulley from turning
by
compressing drive
belt then torque pump pulley bolts
to 25 ft. lbs.
• Recheck drive belt tension
and
adjust
if
required.
Air Manifold, Hose and Tube
Inspection (Fig. 4)
• Inspect
all
hoses
for
deterioration
or
holes.
• Inspect
all
tubes
for
cracks
or
holes.
PUMP
HOUSING
91
DRIVE V
HUB
PRESSURE
RELIEF VALVE
•H
PUMP
'
Mm ^
COVER
A.
J^HTEXHAUST
wBBE
TUBES
SB
^1 INTAKE
JH TUBE
• Check
all
hose and tube connections.
• Check
all
tube
and
hose routing. Interference
may
cause wear.
•
If a
leak
is
suspected
on the
pressure side
of the
system
or any
tubes and/or hoses have been discon-
nected
on the
pressure side,
the
connections should
be checked
for
leaks with
a
soapy water solution.
With
the
pump running, bubbles will form
if
aleak
exists.
Replacement
•
To
replace
any
hose and/or tube, note routing then
remove hose(s) and/or tube(s)
as
required.
CAUTION:
The 1/4"
pipe threads
at the
cylin-
der head
(In
Line)
or
exhaust manifold
(V8) are
VALVE
IN
OPEN
POSITION
INLET
VALVE
IN
CLOSED
POSITION
DIAPHRAGM
POSITIONS
SIGNAL
LINE
CONNECTION
ALVE
Fig.
2—Air Injection Pump
Fig.
3—Mixture Control Valve
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-14
VOLTMETER
WIRING HARNESS
CONNECTOR
Fig.
12c—Field Relay Closing Voltage Test
FIELD RELAY CHECKS AND ADJUSTMENT
To check for a faulty relay proceed as follows:
1.
Connect a voltmeter into the system at the regulator
No.
2 terminal to ground (fig. lie).
2.
Operate the engine at fast idle (1500 to 2000 rpm) and
observe voltmeter reading.
3.
If voltmeter shows zero voltage at regulator, check
circuit between No. 2 terminal on regulator to "R"
terminal on Delcotron.
4.
If voltage at regulator exceeds closing voltage
Fig.
13c—Adjusting Field Relay Closing Voltage
specification and light remains on, regulator field
relay is faulty (Refer to specifications). Check and
adjust regulator as follows:
CLOSING VOLTAGE ADJUSTMENT
•1.
Make connections as shown in Figure 12c using a 50
ohm variable resistor.
NOTE: This gives us a variable resistance in
series from a hot lead to the relay coil.
2.
Turn resistor to "open" position.
3.
Turn ignition switch off.
4.
Slowly decrease resistance and note closing voltage
of the relay. Adjust by bending heel iron in the man-
ner illustrated in Figure 13c.
OTHER HARNESS CHECKS
Other wires in the charging system harness need be
checked for continuity by use of an ohmmeter or a test
ligjit (12 Volt). Connect the test so the wire in question is
in series in the test circuit.
SERVICE OPERATIONS
Service Procedures described in this section are for
the 5.5" aluminum and 6.2" perforated stator Delcotrons
(fig. 14c). Where important differences are encountered
separate mention will be made of the two generators.
GENERATOR
REMOVAL AND INSTALLATION
1.
Disconnect the battery ground strap at battery to
prevent damaging diodes.
2.
Disconnect wiring leads at Delcotron.
3.
Remove generator brace bolt, (if power steering
equipped, loosen pump brace and mount nuts) then
detach drive belt (belts).
4.
Support the generator and remove generator mount
bolt (6.2" Delcotron uses 2 mount bolts) and remove
from vehicle.
5.
Reverse the removal procedure to install then adjust
drive belt.
PULLEY REPLACEMENT
5.5" Delcotron
Single Groove Pulley
1.
Place 15/16" box wrench on retaining nut and insert
a 5/16" alien wrench into shaft to hold shaft while
removing nut (fig. 15c).
2.
Remove washer and slide pulley from shaft.
3.
Reverse Steps 1 and
2
to install, use a torque wrench
with a crow-foot adapter (instead of box wrench) and
torque the nut to 50 ft. lbs. (fig. 16c).
Double Groove Pulley
1.
Place a 15/16" socket (with wrench flats on the drive
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-15
L
RELAY
TERMINAL "F" TERMINAL
"BAT" \ ' /
TERMINAL
/ / /
GRD7
TERMINAL
5.5" SERIES ID DELCOTRON
"BAH"
TERMINAL
^Vs^^^^lijBii^^8C^3^SH|j^^^^^^sH^^Bf- y/
RELAY ^^^"^^^jWwIi^^^^ RELAY
6.2" SERIES 2D, TYPE 150 DELCOTRON
Fig.
14c—Delcotrons - Full View
end or use Adapter J-21501 and a box wrench) on re-
taining nut, insert a 5/16" alien wrench through
socket and adapter into hex on shaft to hold the shaft
while removing the nut.
2.
Remove washer and slide pulley from shaft.
3.
To install, slide pulley and washer on shaft and start
the nut.
4.
Use the socket and adapter with a torque wrench and
tighten-nut to 50 ft. lbs. torque.
BRUSH
REPLACEMENT
6.2"
Delcotron
1.
Remove two nuts retaining the blade connectors and
remove the connectors (fig. 17c). Slide the indicator
light relay wire from the terminal post.
2.
Remove two screws retaining the capacitor and brush
holder to rear end frame, Remove brush holder.
3.
To install brushes, push brushes into holder and
install pin to keep the brushes in holder.
4.
Attach brush assembly and condenser to the end
frame with hex-head stud on the .left side only.
Fig.
15c—Pulley Removal
Fig.
16c—Torqulng Pulley Nut
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL
6Y-31
CAUTION: Before adjusting gap, me center
INSTALLATION
electrode flat. In adjusting the spark pluig Install the spark plugs in the engine with new gaskets
gap,
never bend the center electrode which and tighten to specifications. If torque wrench is not
extends through the porcelain center. Always available, tighten plugs finger tight and 1/2 turn more.
make adjustment by bending the ground or , Plugs are of a 14 millimeter size and care must be
side electrode. exercised when installing or the gap setting may be
changed.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-33
O
V-8 ENGINE
STARTING MOTOR
Fig.
2s—V-8 Starting Circuit Diagram
2.
3.
From battery negative post
To
starting motor
housing.
From solenoid battery terminal
To
solenoid motor
terminal.
If voltage drop
in
any
of
above check exceeds 0.2 volts,
excessive resistance
is
indicated in that portion
of
start-
ing circuit
and the
cause
of the
excessive resistance
should
be
located
and
corrected
in
order to obtain maxi-
mum efficiency in the circuit.
CAUTION:
Do not
operate
the
starting motor
continuously
for
more than
30
seconds
to
avoid
overheating.
When
the
solenoid fails
to
pull
in, the
trouble may be
due
to
excessive voltage drop in the solenoid control cir-
cuit.
To
check
for
this condition, close
the
starting
switch
and
measure
the
voltage drop between
the
BAT-
TERY terminal of the solenoid and the
SWITCH (S)
termi-
nal
of
the solenoid.
1.
If
this voltage drop exceeds 3.5 volts, excessive
re-
sistance
in the
solenoid control circuit
is
indicated
and should be corrected.
2.
If the
voltage drop does not exceed 3.5 volts and the
solenoid does not pull in, measure the voltage availa-
ble
at
the SWITCH terminal
of
the solenoid.
3.
If the
solenoid does
not
feel warm,
it
should pull
in
whenever the voltage available
at
the SWITCH termi-
nal
is 7.7
volts
or
more. When
the
solenoid feels
warm,
it
will require
a
somewhat higher voltage
to
pull in.
STARTING MOTOR AND SOLENOID CHECK
The following checks
may be
made
if the
specific
gravity of the battery
is
1.215
or
higher.
1.
If the
solenoid does
not
pull in, measure the voltage
between
the
switch
(S)
terminal
of the
solenoid
and
ground with the starting switch closed.
CAUTION:
If the
solenoid feels warm, allow
to
cool before checking.
If
the
voltage
is
less than 7.7 volts, check for ex-
cessive resistance
in the
solenoid control circuit.
If
the
voltage exceeds 7.7 volts, remove the starting
motor
and
check
(1)
solenoid current draw,
(2)
starting motor pinion clearance,
and (3)
freedom of
shift lever linkage.
2.
If
the solenoid "chatters" but does not hold in, check
the solenoid
for an
open "hold-in" 'winding. When-
ever
it is
necessary
to
replace
a
starting motor
solenoid, always check starting motor pinion
clearance.
3.
If
motor engages
but
does
not
crank
or
cranks
slowly, check
for
excessive resistance
in the ex-
ternal starting circuit, trouble within
the
starting
motor,
or
excessive engine resistance
to
cranking.
SERVICE OPERATIONS
STARTING MOTOR
REMOVAL AND INSTALLATION (Fig.
3s)
The following procedure
is a
general guide
for all
vehicles
and
will vary slightly depending
on
series
and
model.
1.
Disconnect battery ground cable at battery.
2.
Raise vehicle
to a
good working height.
3.
Disconnect all wires
at
solenoid terminals.
NOTE: Reinstall
the
nuts
as
each wire
is
dis-
connected
as
thread size
is
different but may be
mixed and stripped.
4.
Loosen starter front bracket (nut on V-8 and bolt on
L-6) then remove two mount bolts.
5.
Remove
the
front bracket bolt
or nut and
rotate
bracket clear
of
work area then lower starter from
vehicle
by
lowering front end first
—
(hold starter
against bell housing
and
sort
of
roll end-over-end).
6. Reverse
the
removal procedure
to
install. Torque
the mount bolts
to
25-35
ft.
lbs. first, then torque
brace bolt.
7.
Check operation
of
starter on vehicle.
Fig.
3s—Starter Mounting
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-2
Fig.
2 - Chevelle Clutch Pedal Free Travel Adjustment (V-8 Shown)
some clearance between cross shaft and both its
mounting brackets.
CLUTCH LINKAGE ADJUSTMENT
There is one linkage adjustment (clutch fork push rod
or pedal push rod) to compensate for all normal clutch
wear.
The clutch pedal should have
1-1/4"
free travel (meas-
ured at clutch pedal pad) before the throwout bearing en-
gages the clutch diaphragm spring levers. Lash is re-
quired to prevent clutch slippage which would occur if the
bearing was held against the fingers and to prevent the
bearing from running continually until failure.
Chevrolet Linkage Adjustment (Fig. 1}
With Nuts (A) & (B) loose on Rod (D)
&
before installa-
tion of Clutch Pedal Return Spring
(E),
apply approximately
5 lbs. load in direction of arrow (F) to eliminate clear-
ance between throwout bearing and clutch fingers. Move
Rod (D) in direction of arrow (G) until Clutch Pedal Arm
makes contact with Bumper Stop on instrument panel
brace. Run Nut (B) toward Swivel until dimension (X) is
9/32". Tighten Nut (A) to lock Swivel (C) against Nut (B).
Install Clutch Pedal Return Spring (E).
The foregoing procedure will provide a free pedal
travel of 1" to
1-1/2"
measured on a perpendicular from
the crown of the, pedal pad to the bare metal toe pan.
Chevelle Linkage Adjustment (Fig. 2)
1.
Disconnect spring between cross shaft lever and
clutch fork.
2.
Loosen push rod locknut about three turns.
3.
If there is no free travel, shorten the rod (by turning
at square wrench area) until it is free of clutch fork.
4.
Hold the clutch fork rearward to move throwout
lightly against clutch release fingers, then adjust rod
length until rod just touches ,its seat in the fork.
5.
Adjust locknut to obtain approximately 3/16" clear-
ance between nut and rod sleeve end.
6. Turn the rod with wrench, until the nut just comes in
contact with rod sleeve end, then hold the rod with
wrench and tighten locknut.
7.
Check free pedal travel at pedal (1" to
1-1/2"
is
proper clearance). Readjust if necessary.
Chevy II Linkage Adjustment (Fig. 3}
L-4 & L-6 Models
1.
Loosen locknut "A" and lengthen or shorten push rod
in swivel as required by turning with wrench on ma-
chined flat "B". (Shorten push rod to increase pedal
lash).
2.
Hold push rod at flat "B" and tighten locknut "A".
3.
Recheck pedal free travel.
NOTE: A measurement of approximately 3/16"
between push rod and its seat in fork will give
required pedal free travel.
V-8 Models
The eight cylinder linkage has a two-piece clutch fork
push rod (fig. 3). Adjust clutch pedal free travel by turn-
ing the adjusting rod portion of the push rod to obtain apr
proximately 3/16" clearance between clutch fork and end
of rod, ttien tighten locknut to 8-12 lbs. ft. and check free
travel at pedal. Pedal free travel on all models should
be 1" to
1-1/2".
Corvette Linkage Adjustment
Refer to fig. 1 and the following procedure:
1.
Disconnect pedal return spring.
2.
With Nuts (A) and (B) loose on Rod (D) apply push
hard load in direction of arrow (F) to eliminate
clearance between throwout bearing and clutch
fingers.
3.
Run Nut (B) towards Swivel (C) until dimension (X)
is 3/8" to 7/16".
4.
Tighten Nut (A) to lock swivel against Nut (B).
5.
Connect pedal return spring and check pedal free
travel for
1-1/4"
minimum to 2" maximum.
6. Check every 3,000 miles.
7.
Adjust free travel to 2" to 2-1/2" for heavy duty op-
eration. The return spring may be removed for
heavy duty conditions.
Camaro Linkage Adjustment
Refer to Figure 4 and the following procedure:
Apply a 10 lb. load in direction of Arrow (E) to hold
Clutch Pedal against Clutch Pedal Bumper.
Apply a 10 lb. load to Clutch Fork in direction of Arrow
(D) to eliminate clearance between throwout bearing and
clutch fingers.
Insert a .198 Spacer (F) between clutch fork and Ad-
justing Rod (A).
Rotate Adjusting Rod against Spacer until it has a 5 in.
lb.
torque.
Hold Adjusting Rod and tighten Nut (C) against Swivel
(B) or Rod (B).
Remove Spacer. Install return spring and extension to
clutch fork.
Pedal will have approximately 1" to
1-1/8"
free travel.
A clutch that has been slipping prior to free play ad-
justment may still slip right after the new adjustment due
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-3
DETENT CAM
DETENT SPRING
DETENT CAM
2-3 SHIFT
FORK
DETENT CAM
PIVOT PIN
1ST & REV. 1ST& REV.
SHIFTER SHAFT SHIFT FORK
DETENT CAM
RETAINER RING
2-3 SHIFTER SHAFT
Fig. 3A
•*
Transmission Side Cover, Shift Fork and Detent Assembly
5. Reinstall propeller shaft and any items removed to
obtain clearance.
TRANSMISSION SIDE COVER
Removal •
1.
Disconnect control rods from levers; remove 2-3
cross shaft (Chevrolet)
2.
Shift transmission into neutral detent positions before
removing cover.
3.
Remove cover assembly from transmission case
carefully and allow oil to drain.
Disassembly (Fig. 3A)
1.
Remove the outer shifter levers.
2.
Remove both shift forks from shifter shaft assem-
blies.
Remove both shifter shaft assemblies from
cover. "OM ring seals around shifter shaft may now
be pryed out if replacement is required because of
damage.
3.
Remove detent cam spring and pivot retainer "C"
ring. Remove both detent cams.
4.
Replace damaged parts.
Assembly (Fig. 3A)
1.
With,
detent spring tang projecting up over the
2nd
and
3rd shifter shaft cover opening install the first and
reverse detent cam onto the detent cam pivot pin.
With the detent spring tang projecting up over the
first and reverse shifter shaft cover hole install the
2nd an£ 3rd detent cam.
2.
Install detent cam retaining "C" ring to pivot shaft,
and hook spring into detent cam notches.
3.
Install both shifter shaft assemblies in cover being
careful not to damage seals. Install both shift forks
to shifter shaft assemblies^ lifting up on detent cam
to allow forks to fully seat into position.
4.
Install outer shifter levers, flat washers, lock wash-
ers and bolts.
Installation
1.
Shift shifter levers into neutral detent (center) posi-
tion.
Position cover gasket on case.
2.
Carefully position side cover into place making sure'
the shift forks are aligned with their respective
mainshaft clutch sliding sleeves.
3.
Install cover attaching bolts and tighten evenly to
specified torque.
4.
Remove filler plug and add lubricant specified in
Section 0, to level of filler plug hole.
COMPONENT PART REPLACEMENT
TRANSMISSION REPLACEMENT (EXC. CORVETTE)
Removal From Vehicle
1.
Remove propeller shaft assembly.
2.
Disconnect speedometer cable at transmission.
3.
Disconnect shifter rods at transmission levers.
4.
Support engine assembly.
5. Remove transmission to clutch housing bolts.
6. Remove transmission crossmember to mount bolts.
7. Loosen transmission crossmember and move rear-
ward or remove.
8. Slide transmission rearward and remove.
Installation in Vehicle
1.
Raise transmission into position and slide forward
piloting clutch gear retainer into clutch housing.
2.
Install transmission to clutch housing retaining bolts
and lock washers, torque to 50 ft. lbs.
3.
Repositioning transmission crossmember and install
retaining bolts.
4.
Install transmission crossmember to mount bolts.
5. Connect and adjust shift rods at transmission levers
and cordon shaft to 2nd and 3rd lever on Chevrolet
Models. (Fig. 4A)
Fig. 4A - Chevrolet 2-3 Shift Lever Cordon Shaft
CHEVROLET CHASSIS SERVICE MANUAL