1967 CHEVROLET CAMARO spark plugs

ENGINE-ELECTRICAL
6Y-4

CLEANING

The external condition of the Battery should be checked

periodically for damage or for the presence of dirt and

corrosion. The top of the Battery should be kept clean.

An accumulation of acid film and dirt may permit current

to flow between the terminals, which will slowly dis-

charge the Battery. For best results when cleaning the

top of Batteries, wash first with a diluted ammonia or a

soda solution to neutralize any acid present; then flush

with clean water. Care must be taken to keep vent plugs

tight, so that the neutralizing solution does not enter the

cells.

CABLES

To insure good electrical contact, the cables should be

clean and tight on the Energizer posts. If the posts or

cable terminals are corroded, the cables should be dis-

connected and the terminals and clamps cleaned sepa-

rately with a soda solution and a wire brush. After

cleaning and installing clamps, apply a thin coating of

petroleum jelly on the cable clamps to retard corrosion.

CARRIER
AND
HOLD-DOWN

The Battery carrier and hold-down should be clean and

free from corrosion before installing the Battery. The

carrier should be in a sound mechanical condition so that

it will support the Battery securely and keep it level.

To prevent the Battery from shaking in its carrier,

the hold-down bolts should be tight (60-80 in. lbs.). How-

ever, the bolts should not be tightened to the point where

the Battery case or cover will be placed under a severe

strain.

BATTERY SAFETY PRECAUTIONS

When Batteries are being charged, an explosive gas

mixture forms in each cell. Part of this gas escapes

through the holes in the vent plugs and may form an

explosive atmosphere around the Battery itself if ventila-

tion is poor. This explosive gas may remain in or around

the Battery for several hours after it has been charged.

Sparks or flames can ignite this gas causing an internal

explosion which may shatter the Battery.

The following precautions should be observed to pre-

vent an explosion:

1.
Do not smoke near Batteries being charged or which

have been very recently charged.

2.
Do not break live circuits at the terminals- of Batr

teries because a spark usually occurs at the point

where a live circuit is broken. Care must always be

taken when connecting or disconnecting booster leads

or cable clamps on fast chargers. Poor connections

are a common cause of electrical arcs which cause

BATTERY CHARGING PROCEDURES

There are three methods of recharging Batteries.

They differ basically in the length of time the Battery is

charged and the rate at which charging current is sup-

plied. One is the Slow Charge method, the second is the

Fast Charge method, and the third is the Emergency

Boost Charge method.

Before recharging a Battery by any method, the elec-

trolyte level must be checked and adjusted if necessary.
SLOW CHARGING

The Slow Charge method supplies the Battery with a

relatively low current flow for a relatively long period of

time. This is the only method that will bring the Battery

to a full state of charge.

The Slow Charge method consists of charging at

approximately a 4 ampere rate for 24 hours or more if

necessary to bring the Battery to full charge. A fully

charged condition is reached when the cells are gassing

freely and three corrected specific gravity readings

taken at hourly intervals show no increase.

FAST CHARGING

The Fast Charge method supplies current to the Bat-

tery at a 40 to 50 ampere rate for a 1 1/2 hour period of

time. If the electrolyte temperature reaches 125°F before

the 1 1/2 hour period is completed, the Battery must be

taken off charge temporarily, or the charging rate

reduced to avoid damage to the Battery.

Although a Battery cannot be brought to a fully charged

condition during Fast Charge, it can be substantially

recharged or "boosted". In order to bring the Battery to

a fully charged condition, the charging cycle must be

finished by the Slow Charge method.

EMERGENCY BOOST CHARGING

In cases where the Battery is not sufficiently charged

to crank the engine, an emergency boost charge may be

applied as a temporary expedient in order to crank the

engine. The Emergency Boost Charge method consists of

charging at a 40 to 50 ampere rate for a period of one-

half hour.

It should be particularly noted that the Emergency

Boost Charge will not necessarily restore the Battery to

a useful state of. charge for continued service. After an

emergency boost charge, failure to charge the Battery

further, either by a long uninterrupted driving period or

by the Fast Charge or Slow Charge method, may result

in failure to crank the engine the next time cranking is

attempted. A Battery should never be condemned on the

basis of failure to crank the engine after an emergency

boost charge. Although an emergency boost charge may

put enough energy into the Battery to crank the engine

once, further charging usually is necessary in order to

create a sufficient reserve to crank a second and third

time.

12
VOLT BATTERY SUGGESTED

CHARGING RATES

(100 Amp/hr or Less Capacity)

TYPE OF

CHARGE

Boost Charge for

Light Load Test

Slow Charge

Fast Charge

Quick Boost .

Dry Charge

Warm-up Boost
LENGTH

OF TIME

20 Minutes

24 Hours

1-1/2 Hours

30 Minutes

10 Minutes
CHARGING

RATE

50 Amps

4 Amps

40-50 Amps

40-50 Amps

15 Amps

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-18

IGNITION SYSTEMS

INDEX

Page

General Description . 6Y-18

Maintenance and Adjustments 6Y-19

Breaker Point System 6Y-19

Breakerless System . . 6Y-X9

Ignition Coil Check 6Y-19

Spark Plugs 6Y-19

Service Operations , 6Y-19

Distributor Contact Points . 6Y-19

Cleaning 6Y-19

Replacement 6Y-20

Setting Dwell Angle 6Y-21

Distributor Condenser 6Y-22

Performance Diagnosis. 6Y-22

Replacement . . 6Y-23

Distributor

Breaker Point Type 6Y-23

Removal. . 6Y-23

Disassembly • 6Y-23
Page

Cleaning and Inspection .....'.., 6Y-25

Assembly . 6Y-25

Installation 6Y-26

Breakerless i 6Y-27

Removal . 6Y-27

Disassembly and Assembly 6Y-27

Installation 6Y-27

Off-Engine Test. . 6Y-27

Coil Replacement 6Y-27

Pulse Amplifier. 6Y-28

Disassembly .6Y-4S8

Component Checks
!
6Y-28

Assembly 6Y-29

Ignition Switch Replacement 6Y-29

Spark Plugs 6Y-30

Cleaning and Regapping I ....... 6Y-30

Installation . 6Y-31

GENERAL DESCRIPTION

There are two ignition systems available on 1967

vehicles. The breaker point type which is continued as

the regular production system and the optional (Corvette

only) transistor controlled breakerless ignition system

(magnetic pulse type). The transistor ignition system

features a specially designed distributor, control unit

(ignition pulse amplifier), and a special coil. Two resist-

ance wires are also used in the circuit; one as a ballast

between the coil negative terminal and ground, while the

other resistance wire provides a voltage drop for the

engine run circuit and is by-passed at cranking. The

other units in the system (the ignition switch, spark

plugs,
and battery) are of standard design. The dis-

tributor and control unit (ignition pulse amplifier) are

shown in Figures li and 2i.

CAP-

VACUUM

PICK-UP

COIL LEADS

PICK-UP COIL

CONNECTOR BODY
Although the external appearance of the distributor

resembles a standard distributor, the internal construc-

tion is quite different. As shown in the exploded view

(fig. 16i) an iron timer core replaces the conventional

breaker cam. The timer core has the same number of

equally-spaced projections, or vanes as engine cylinders.

The timer core rotates inside a magnetic pickup as-

sembly, which replaces the conventional breaker plate,

contact point set, and condenser assembly. The magnetic

pickup assembly consists of a ceramic permanent mag-

net, a pole piece, and a pickup coil. The pole piece
is.
a

steel plate having equally spaced internal teeth, one tooth

for each cylinder of the engine.

The magnetic pickup assembly is mounted over the

main bearing of the distributor housing, and is made to

rotate by the vacuum control unit, thus providing vacuum

advance. The timer core is made to rotate about the shaft

by conventional advance weights, thus providing centrifu-

gal advance.

Fig.
li—
Magnetic Pulse Distributor
Fig.
2i-lgnition Pulse Amplifier Unit

CHEVROLET CHASSIS SERVICE MANUAL

MAINTENANCE AND ADJUSTMENTS
ENGINE-ELECTRICAL 6Y-19

PERIODIC MAINTENANCE

BREAKER POINT SYSTEM

The distributor breaker points and spark plugs are the

only ignition system components that require periodic

service. The remainder of the ignition system requires

only periodic inspection to check operation of the units,

tightness of the electrical connections, and condition of

the wiring. When checking the coil, test with a reputable

tester.

Breaker type distributors are equipped with cam lubri-

cator and should have the wick replaced at the same time

contact point set is replaced. It is not necessary to

lubricate the breaker cam when using a cam lubricator.

Do not attempt to lubricate the wick - Replace when

necessary. When installing a new wick, adjust its posi-

tion so the end of the wick just touches the lobe of the

breaker cam.

Distributor shaft lubrication is accomplished by a

reservoir of lube around the mainshaft in the distributor

body.

BREAKERLESS SYSTEM

Since there are no moving parts in the ignition pulse

amplifier unit mounted forward of the radiator bulkhead,

and the distributor shaft and bushings have permanent

type lubrication, no periodic maintenance is therefore

required for the breakerless ignition system. The dis-

tributor lower bushing is lubricated by engine oil through

a splash hole in the distributor housing, and a housing

cavity next to the upper bushing contains a supply of

lubricant which will last between overhaul periods. At

time of overhaul, the upper bushing may be lubricated

by removing the plastic seal and then adding SAE 20 oil

to the packing in the cavity. A new plastic seal will be

required since the old one will be damaged during

removal.

Tachometer readings for test purposes can be made on

the primary circuit of the breakerless ignition system in

the same manner as on the conventional ignition system,

however before attempting to connect a test tachometer

into the primary circuit check with your instrument

supplier to insure that satisfactory readings can be

obtained and the breakerless system will not be damaged

by the tachometer that is to be used,

IGNITION COIL CHECK (BREAKERLESS)

The ignition coil primary can be checked for an open
PULSE

AMPLIFIER

IGN. SWITCH WIRE

"("IGN" TERMINAL)
-E3 IJU
12
WHITE-

-20 BLACKf' • 12 WHITE-

Fig.
3i—
Breakerless Ignition System

condition by connecting an ohmmeter across the two

primary terminals with the battery disconnected. Pri-

mary resistance at 75
°F.
should be between .35 and .55

ohm. An infinite reading indicates the primary is open.

For the engine to run but miss at times, the primary

open may be of the intermittent type.

The coil secondary can be checked for an open by con-

necting an ohmmeter from the high tension center tower

to either primary terminal. To obtain a reliable reading,

a scale on the ohmmeter having the 20,000 ohm value

within, or nearly within, the middle third of the scale

should be used. Secondary resistance at 75°F. should be

between
8,000
and 12,500 ohms. If the reading is infinite,

the coil secondary winding is open.

A number of different types of coil testers are avail-

able from various test equipment manufacturers. When

using these testers, follow the procedure recommended

by the tester manufacturer.

tester will properly
NOTE:
Make sure the

check this special coil.

SPARK PLUGS

Should be removed, inspected cleaned and regapped at

tune-up. Defective plugs should be replaced, see Servic-

ing of Units Off the Vehicle.

SERVICE OPERATIONS

DISTRIBUTOR CONTACT POINTS

CLEANING

Dirty contact points should be dressed with a few

strokes of a clean, fine-cut contact file. The file should

not be used for other metals and should not be allowed to

become greasy or dirty. Never use emery cloth to clean

contact points. Contact surfaces, after considerable use,

may not appear bright and smooth, but this is not neces-
sarily an indication that they are not functioning satis-

factorily. Do not attempt to remove all roughness nor

dress the point surfaces down smooth; merely remove

scale or dirt.

Badly burned or pitted contact points should be re-

placed and the cause of trouble determined so it can be

eliminated. High resistance or loose connections in the

condenser circuit, oil or foreign materials on the contact

surfaces, improper point adjustment or high voltages may

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL-6Y-30

Fig.
2 li—Removing Ignition Switch Nut

4.
Remove heater and/or A/C control panel assembly

retaining screws and push panel assembly from

console.

NOTE: If interference between control panel

and radio is encountered, loosen radio retaining

nuts.

5.
Remove radio control knobs, bezels and retaining

nuts.

6. Disconnect radio wiring harness and antenna lead-in.

7.
Remove radio rear brace attaching screw and re-

move radio from vehicle.
Fig.
231—Switch and Connector Unplugged

8. Remove ignition switch bezel nut using Tool J-7607

and push switch rearward from panel opening.

9. Disconnect wiring connector from rear of switch.

10.
To install, reverse removal procedure.

SPARK PLUGS

CLEANING AND REGAPPING

Clean the spark plugs thoroughly, using an abrasive-

type cleaner. If the porcelains are badly glazed or

blistered, the spark plugs should be replaced. All spark

plugs must be of the same make and number or heat

range. Use a round feeler gauge to adjust the spark plug

gap to specifications (fig. 24i).

Fig.
22i—Unlocking Ignition Switch Connector

Fig.
241—Setting Sfxirk Plug Gap

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