1967 CHEVROLET CAMARO check engine

ENGINE-ELECTRICAL 6Y-24

Fig.
13I-V-8 Distributor (Typical)-Exploded View

1.

2.

2a.

3.

4.
Condenser

Contact Point Assembly

Cam Lubricator

Retaining Ring

Breaker Plate
5.

5a.

6.

7.
Felt Washer

Plastic Seal

Vacuum Advance

Unit

Housing
8.^
Shim
Washer

9. Drive Gear Pin

10.
Drive Gear

11.
Cap

12.
Rotor
13.
Weight Springs

14.
Mainshaft

15.
Advance Weights

16.
Cam Weight

Base Assembly

When mounting distributors for tests, first secure the

gear in the test drive mechanism, then push the distribu-

tor housing downward toward the gear to take up any end

play between the gear and the housing.

NOTE:
When testing distributors that have

their lower shaft support bushing located in the

engine block (6 cylinder engines), a special

adapter should be used to insure the shaft will

run true in its housing.

Test the distributor for variation of spark, correct

centrifugal and vacuum advance and condition of contacts.

This test will give valuable information on distributor

condition and indicate parts replacement which may be

necessary. Check the area on the breaker plate just

beneath the contact points. A smudgy line indicates that

oil or crankcase vapors have been present between the

points.

Four and Six Cylinder Engines

Refer to Figure 12i.

1.
Remove the rotor.
2.

3.
Remove the vacuum control assembly retaining

screws, detach the unit from the distributor housing.

Disconnect the primary and condenser leads from the

contact point quick disconnect terminal, remove the

contact point set attaching screw, condenser attach-

ing screw. Remove the point set and condenser from

the breaker plate.

Remove the breaker plate attaching screws, remove

the breaker plate from the distributor housing (fig.

NOTE:
Do not disassemble breaker plate any

further.

5. Remove the roll pin retaining the driven gear to the

mainshaft, slide the gear from the shaft.

6. Slide the cam and mainshaft from the distributor

housing.

7. Remove the weight cover, and stop plate screws, re-

move the cover, weight springs, weights and slide

cam assembly from the mainshaft.

V-8 Engines

Refer to Figure 13i.

CHEVROLET CHASStS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-25

1.
Remove the rotor.

2.
Remove both weight springs and advance weights.

3.
Remove roll pin retaining driven gear to distributor

shaft, slide the gear and spacers from the shaft.

Remove tachometer drive gear on Corvette models.

4.
Before sliding the distributor shaft from the hous-

ing, check for and remove any burrs on the shaft.

This will prevent damage to the seals and bushing

still positioned in the housing.

5. Slide the distributor mainshaft and cam-weight base

assembly from the housing.

6. Remove vacuum advance mechanism retaining

screws, remove the vacuum advance assembly.

7. Remove the spring retainer, remove the breaker

plate assembly from the distributor housing. Re-

move the contact point and condenser from the

breaker plate. Remove the felt washer and plastic

seal located beneath the breaker plate.

CLEANING AND INSPECTION

1.
Wash all parts in cleaning solvent except cap, rotor,

condenser, breaker plate assembly and vacuum con-

trol unit. Degreasing compounds may damage insula-

tion of these parts or saturate the lubricating felt in

the case of the breaker plate assembly.

2.
Inspect the breaker plate assembly for damage or

wear and replace if necessary.

3.
Inspect the shaft for wear and check its fit in the

bushings in the distributor body. If the shaft or bush-

ings are worn, the parts should be replaced.

4.
Mount the shaft in "V" blocks and check the shaft

alignment with a dial guage. The run-out should not

exceed .002".

5. Inspect the advance weights for wear or burrs and

free fit on their pivot pins.

6. Inspect the cam for wear or roughness. Then check

its fit on the end of the shaft. It should be absolutely

free without any roughness.

7. Inspect
the •
condition of the distributor points. Dirty

points should be cleaned and badly pitted points

should be replaced. (See Distributor Contact Points.)

8. Test the condenser for series resistance, micro-

farad capacity (.18 to .23) and leakage or breakdown,

following the instructions given by the manufacturer

of the test equipment used.

9. Inspect the distributor cap and sparkplug wires for

damage and replace if necessary.

ASSEMBLY

Four and Six Cylinder Engine

Refer to Figure 12i for Exploded View of Distributor.

1.
Replace cam assembly to mainshaft.

NOTE:
Lubricate top end of shaft with Delco

cam and ball bearing grease or equivalent prior

to replacing.

2.
Install governor weights on their pivot pins, replace

weight springs. Install weight cover and stop plate.

3.
Lubricate mainshaft and install it in distributor

housing.

4.
Install distributor driven gear to mainshaft and in-

sert attaching roll pin. Check to see that shaft turns

freely.
5. Install breaker plate assembly in the distributor body

and attach retaining screws.

6. Attach condenser and contact point set in proper lo-

cation with appropriate attaching screws.

NOTE:
Contact point set pilot must engage

matching hole in breaker plate. Connect primary

and condenser leads to contact set quick-

disconnect terminal.

7. Attach vacuum control assembly to distributor

housing.

8. Check and adjust contact point opening and align-

ment (See setting and alignment of points.)

9. Check breaker lever spring tension which should

be.
19-23 ounces. (See contact point replacement.)

V-8 Assembly-(Fig. 13i)

1.
Fill housing lubricating cavity with proper compound,

press in new plastic seal and install felt washer.

2.
Replace the vacuum advance unit, install the breaker

plate in housing and install the spring retainer on

the upper bushing.

3.
Lubricate and slide weight cam over mainshaft and

install weights and spring (fig. 14i).

4.
Insert mainshaft into housing, indexing it with drive

gear and washers. Install tachometer drive gear on

Corvette models.

5. Slide distributor drive gear shims and gear over

shaft and install new pin. Tap new pin through gear

and mainshaft. Check shaft for free rotation.

NOTE:
Mainshaft end clearance should be

.002"-.007". Add or remove shims as necessary.

6. Install contact point set and condenser to breaker

plate. Connect leads as shown in Figure 6i.

NOTE:
Contact point spring tension is factory-

set above specifications to assure ease of final

adjustment. Correct tension is 19-23 oz.

7. Install rotor to cam assembly, indexing round and

square pilot holes.

Flg.
Hi-Advance Weights Installed

CHEVROLET CHASSIS SERVICE

ENGINE-ELECTRICAL 6Y-27

timing mark on pulley lines up with timing tab.

2.
Position distributor to opening in block in normal

installed attitude (fig. 15i), noting position of vacuum

control unit.

3.
Position rotor to point toward front of engine (with

distributor housing held in installed attitude), then

turn rotor counter-clockwise approximately 1/8 turn

more toward left cylinder bank and push distributor

down to engine camshaft. It may be necessary to ro-

tate rotor slightly until camshaft engagement is felt.

4.
While pressing firmly down on distributor housing,

kick starter over a few times to make sure oil pump

shaft is engaged. Install hold-down clamp and bolt

and snug up bolt.

5. Turn distributor body slightly until points just open

and tighten distributor clamp bolt.

6. Place distributor cap in position and check to see

that rotor lines up with terminal for No. 1 spark

plug.

7. Install cap, check all high tension wire connections

and connect spark plug wires if they have been re-

moved. It is important that the wires be installed in

their location in the supports.

NOTE:
The brackets are numbered to show the

correct installation. Wires must be installed as

indicated to prevent cross firing.

8. Connect vacuum line to distributor and distributor

primary wire to coil terminal.

9. Start engine and set timing as described under Turn-

Up in Section 6.

BREAKERLESS (MAGNETIC PULSE)

DISTRIBUTOR

REMOVAL (CORVETTE)

1.
If vehicle is equipped with radio, remove three bolts

securing ignition shield over distributor and coil.

One bolt is accessible from the top of shield, the

other two are at rear of shield, facing firewall.

2.
Disconnect tachometer drive cables from distributor

housing.

3.
Disconnect pickup coil leads at connector.

4.
Remove distributor cap.

5. Crank engine so rotor is in position to fire No. 1

cylinder and timing mark on harmonic balancer is

indexed with pointer.

6. Remove vacuum line from distributor.

7. Remove distributor clamping screw and hold-down

clamp.

8. Remove distributor and distributor-to-block gasket.

It will be noted that the rotor will rotate as the

distributor is pulled out of the block. Mark the re-

lationship of the rotor and the distributor housing

after removal so that the rotor can be set in the

same position when the distributor is being installed.

DISASSEMBLY (Fig. 16i)

NOTE:
If a distributor is being disassembled

for replacement of the stationary magnetic

pickup assembly only, it will be necessary to

perform only Steps 3, 4, 5, 7, 8, 9, and 12 of the

service procedure listed below.
1.
Remove screws securing rotor and remove rotor.

2.
Remove centrifugal weight springs and weights.

3.
Remove the tachometer drive gear from the distribu-

tor (Corvette only).

4.
Remove roll pin, then remove distributor drive gear

and washer.

CAUTION: To prevent

magnet, support drive gear
;e to the permanent

?n
driving out roll

pin.

5. Remove drive shaft assembly.

6. Remove centrifugal weight support and timer core

from drive shaft.

7. Remove connector from pickup coil leads.

8. Remove retaining ring which secures magnetic

core support plate to distributor shaft bushing in

housing.

9. As a unit, remove the entire magnetic pickup assem-

bly from the distributor housing.

10.
Remove brass washer and felt pad.

11.
Remove vacuum advance unit.

12.
To reassemble distributor, perform the above steps

in reverse order.

INSTALLATION (CORVETTE)

1.
Check to see that the engine is at firing position for

No.
1 cylinder (timing mark on harmonic balancer

indexed with pointer).

2.
Position a new distributor-to-block gasket on the

block.

3.
Before installing distributor, index rotor with hous-

ing as noted when distributor was removed. Install

distributor in block so that vacuum diaphragm faces

approximately 45° forward on the right side of the

engine and the rotor points toward contact in cap for

No.
1 cylinder.

4.
Replace distributor clamp leaving screw loose

enough to allow distributor to be turned for timing

adjustment.

5. Install spark plug wires in distributor cap. Place

wire for No. 1 cylinder in tower (marked on old cap

during disassembly) then install remaining wires

clockwise around the cap according to the firing

order (1-8-4-3-6-5-7-2).

6. Attach distributor to coil primary wires.

7. Replace distributor cap.

8. Adjust timing and then fully tighten distributor clamp

screw.

9. Attach vacuum line to distributor.

10.
Connect tachometer drive cables to distributor body.

11.
Replace ignition shields.

DISTRIBUTOR OFF-ENGINE TEST

The distributor's centrifugal and vacuum advance can

be checked in a distributor testing machine or synchro-

scope specially adapted or designed to accommodate this

type distributor. However, since this involves removing

the distributor from the engine, this test may be post-

poned until other system checks have been made. A dwell

reading cannot be obtained on this distributor and it is not

likely that the centrifugal or vacuum advance will be a

cause of trouble.

COIL REPLACEMENT

1.
Disconnect ignition switch and distributor leads from

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-28

terminals on eoil. On Corvettes equipped with radio,

remove bolts securing ignition shield over distribu-

tor and coil.

2.
Pull high tension wire from center terminal of coil.

3.
Remove the two coil support mounting bolts or loosen

friction clamp screw and remove coil.

4.
Place new coil in position and install attaching bolts

or tighten clamp screw.

5.
Place high tension lead securely in center terminal

of coil and connect ignition switch and distributor

primary leads to terminals on coil. Replace ignition

shield on Corvettes.

6. Start engine and test coil operation.

IGNITION PULSE AMPLIFIER

DISASSEMBLY

To check the amplifier for defective components, pro-

ceed as follows:

1.
Remove the bottom plate from the amplifier.

2.
To aid in reassembly, note the locations of the lead

connections to the panel board.

3.
Remove the three panel board attaching screws, and

lift the assembly from the housing.

4.
To aid in reassembly, note any identifying markings

on the two transistors and their respective locations

on the panel board and heat sink assembly.

5.
Note the insulators between the transistors.and the

heat sink, and the insulators separating the heat sink

from the panel board.

6. Remove the transistor attaching screws, and sepa-

rate the two transistors and heat sink from the panel

board.

7.
Carefully examine the panel board for evidence of

damage.

MOUNTING

SCREW

RESISTOR R5 jgSfe. / DIODE Dl

TRANSISTOR TR2

(UNDERNEATH)

1H L >©V

[So

To
I
/'%**jt\
\
TRANSISTC>R"""

1 X ^^w^ X \ (UNDERNEATH)

9^ESISTORR^^^H|^^^^^H

^B
RESISTOR
R4
^HPH^^H

WM'
RESISTOR
R3
I^B^^^^I^U

N .6 ®

mm

N%|/MOUNTING

• tr^i^w ^\ vjR SCREW

CAPACITOR
Cl\
pNkj^^A^
\
RESISTOR
Rl

MOUNTING ^55S^^ \ CAPACITOR C3

SCREW I RESISTOR R6 CAPACITOR C2

TRANSISTOR TR3
COMPONENT CHECKS (Figs. \7\ and 18i)

With the two transistors separated from the assembly,

an ohmmeter may be used to check the transistors and

components on the panel board for defects. An ohmmeter

having a 1-1/2 volt cell, which is the type usually found

in service stations, is recommended. The low range

scale on the ohmmeter should be used except where

specified otherwise.

A 25 watt soldering gun is recommended, and a 60% tin

40%
lead solder should be used when re-soldering. Avoid

excessive heat which may damage the panel board. Chip

away any epoxy involved, and apply new epoxy which is

commercially available.

In order to check the panel board assembly, it is

necessary to unsolder at the locations indicated in Fig-

ure 18i the two capacitors C2 and C3. In all of the fol-

lowing checks, connect the ohmmeter as shown and then

reverse the ohmmeter leads to obtain two readings. The

amplifier circuitry is shown in Figure 19i.

1.
Transistors TR1 and TR2: Check each transistor by

referring to Figure 20i. If both readings in Step 1

are zero, the transistor is shorted. If both readings

in Step 2 are zero, the transistor is shorted; and if

both readings are infinite, the transistor is open.

Interpret Step 3 the same as Step 2.

2.
Trigger Transistor TR3:
11
both readings in Step 1

are zero, the transistor is shorted. If both readings

in Step 2 are zero, the transistor is shorted; and if

both readings are infinite, the transistor is open.

Interpret Step 3 the same as Step 2.

3.
Diode Dl: 11 both readings are zero, the diode is

shorted; and if both readings are infinite, the diode

is open.

4.
Capacitor Cl: If both readings are zero, the capaci-

tor is shorted.

5.
Capacitors C2 and C3: Connect the ohmmeter across

CHECKING

RESISTOR Rl

UNSOLDER
I
CHECKING TRIGGER

TRANSISTOR TR3
CHECKING

CAPACITOR C

Fig.
171—Pulse Amplifier Panel Board
Fig.
18i—Pulse
Amplifier
Component
Checks

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-29

each capacitor (not illustrated). The capacitor is

shorted if both readings are zero.

6. Resistor Rl: The resistor is open if both readings

are infinite.

7. Resistor R2: Use an ohmmeter scale on which the

1800 ohm value is within, or nearly within, the

middle third of the scale. If both readings are infi-

nite, the resistor is open.

8. Resistor R3: Use an ohmmeter scale on which the

680 Ohm value is within, or nearly within, the middle

third of the scale. If both readings are infinite, the

resistor is open.

9. Resistor R4: Select an ohmmeter scale on which the

15000 ohm value is within, or nearly .within, the

middle third of the scale. If either reading is infi-

nite, the resistor is open. ~

10.
Resistor R5: Use the lowest range ohmmeter scale.

The resistor is open if either reading is infinite.

NOTE:
This resistor on some applications may

be located in the vehicle wiring harness, and not

on the panel board.

11.
Resistor R6: An ohmmeter scale on which the 150

ohm value is within or nearly within, the middle

third of the scale should be used. If both readings

are infinite, the resistor is open.

REASSEMBLY

During assembly, coat with silicone grease both sides

of the flat insulators used between the transistors and

heat sink, and also the heat sink on the side on which the

transistors are mounted. The silicone grease, which is

available commercially, conducts heat and thereby pro-

vides better cooling.'

IGNITION PULSE AMPLIFIER

R-5

C-3 Ju

MAGNETIC PULSE

DISTRIBUTOR
IGNITION SWITCH REPLACEMENT (Figs.
21
i to 23i)

CHEVROLET, CHEVY II AND CORVETTE

1.
Raise hood and disconnect battery ground cable from

battery.

2.
Remove lock cylinder by positioning switch in "off"

position and inserting wire in small hole in cylinder

face. Push in on wire to depress plunger and con-

tinue to turn key counter-clockwise until lock cylin-

der can be removed.

3.
Remove the metal ignition switch nut from the pas-

senger side of the dash using Tool J-7607 (Fig. 21i).

4.
Pull the ignition switch out from under the dash and

remove the wiring connectors.

5. To remove the "theft resistant" connector, the

switch must be out from under the dash as outlined

in Step 4. Using a screw driver unsnap the locking

tangs on the connector from their position on the

switch as shown in Figure 22i. Unplug the connector.

6. Snap the connector into place on a new ignition

switch.

7. Place the switch into position from behind the dash

and install the metal ignition switch nut.

8. Install the lock cylinder.

9. Install the battery cable to the battery and lower the

hood.

CHEVELLE

1.
Disconnect battery ground cable.

2.
Remove ash tray, retainer attaching screws and

retainer.

3.
Remove A/C distributor duct retaining screws and

duct.

Fig.
19i—Pulse Amplifier Internal Circuitry
Fig.
20i—Transistor Checking

CHEVROLET Oi

ENGINE-ELECTRICAL 6Y-32

STARTER CIRCUIT

INDEX

Page

General Description 6Y-32

Maintenance and Adjustments . '. . 6Y-32

Resistance Checks 6Y-32

Starting Motor and Solenoid Check 6Y-33
Page

Service Operations 6Y-33

Starter Motor 6Y-33

Removal and Installation 6Y-33

GENERAL DESCRIPTION

The function of the starting system, composed of the

starting motor, solenoid and battery, is to crank the

engine. The battery supplies the electrical energy, the

solenoid completes the circuit to the starting motor, and

the motor then does the actual work of cranking the

engine.

The starting motor (fig. Is) consists primarily of the

drive mechanism, frame, armature, brushes, and field

windings. The starting motor is a pad mounted 12-volt

extruded frame type, having four pole shoes and four
fields,
connected with the armature. The aluminum drive

end housing is extended to enclose the entire shift lever

and plunger mechanism, protecting them from dirt,

splash, and icing. The flange mounted solenoid switch

operates the overrunning clutch drive by means of a

linkage to the shaft lever.

The V-8 wiring harness differs from the in-line engine

in that the ignition lead to the coil from the switch is at-

tached at the coil instead of at the starter solenoid (fig.

2s).

CONTACT

FINGER

PINION

STOP

BRUSH

INSULATED BRUSH HOLDER \ FIELD COIL

BRUSH SPRING ARMATURE

GROUNDED BRUSH HOLDER
OVERRUNNING

CLUTCH

Fig.
Is—Starting Motor Cross Section (Typical)

MAINTENANCE AND ADJUSTMENTS

No periodic lubrication of the starting motor or sole-

noid is required. Since the starting motor and brushes

cannot be inspected without disassembling the unit, no.

service is required on these units between overhaul

periods.

RESISTANCE CHECKS

Although the starting motor cannot be checked against
specifications on the car, a check can be made for. exces-

sive resistance in the starting circuit. Place a volt-

meter across points in the cranking circuit as outlined

below and observe the reading with the starting switch

closed and the motor cranking (distributor primary lead

grounded to prevent engine firing).

1.
From battery positive post To solenoid battery

terminal.

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

ENGINE-ELECTRICAL 6Y-34

SPECIAL TOOLS

J-7607

IGNITION SWITCH

NUT REMOVER

J-9717-2

SUPPORT

TOOL
J-9717-1

PRESS

TOOL
J-9600-2

SHOULDERED

INSTALLER
J-21501

PULLY

ADAPTER

J-5184

CHECKING

SCALE

J-21600

HARNESS ADAPTER

Fig. 4s-Specia! Tools

CHEVROLET CHASSIS SERVICE MANUAL