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PART 20-1- MAINTENANCE OPERATIONS
TORQUE INTAKE MANIFOLD
BOLTS
8 CYLINDER ONLY
Refer to Fig. 5 for the correct
tightening sequence. Using a torque
wrench, and following the sequence
given, tighten the manifold
bolts to
specifications.
Intake Manifold Bolt Torque
Engine
(Ft-Lb)
302
351
............
5/
16 bolt 23-25
3/
8 bolt 28-32
CD CD ®0CD
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FIG. 5- Intake Manifold
Torque
Sequence- 302 and 351
Engines
BATTERY CABLES
Check battery cable connections
for tightness.
Check cables for
frayed insulation or excessive corro-
sion. Replace as required.
INSPECT SECONDARY
IGNITION
WIRING
Inspect the secondary (high-ten-
sion) wiring for cracked insulation
or indications of heat damage.
Be
sure that the spark plug wires are
fully seated on the spark plugs and
that the connections to the coil and
distributor are bottomed in
the
receptacles provided.
INSPECT, CLEAN,
ADJUST AND
TEST SPARK
PLUGS- REPLACE
AS REQUIRED
REMOVAL
1. Remove the wire from each
spark plug by grasping, twisting and
then pulling the moulded cap of the
wire only. Do not pull on
the wire
because the wire connection
in-
side the cap may
become sepa-
rated or the weather
seal may
be damaged.
2. Clean the area around each
spark plug port with compressed air,
then remove the spark plugs.
IDENTIFIED BY
BLACK,
DRY FLUFFY 'CARBON
DE POSITS
ON
INSULA TOR
TIPS,
EXPOSED
SHELL
SURFACES
AND ELECTRODES.
CAUSED BY TOO COLD A
PLUG
,
WEAK
IGNITION,
DIRTY
AIR CLEANER,DEFECTIVE FUEL
PUMP, TOO RICH
A
FUEL
MIX TUR!, IMPROPERLY
OPERATING HEAT RISER
OR
EXCESSIVE IDLING.
CAN BE CLEANED.
IDENTIFIED BY
DARK
GRAY
, BLACK,
YELLOW
OR
TAN DE POSITS
OR A
FUSED GLAZED COATING
ON THE INSULATOR TIP.
CAUSED
BY HIGHLY
LEADED
GASOLINE. CAN
BE
CLEANED.
IDENTIFIED BY
MELTEu
OR SPOTTY DEPOSITS
RESEMBLING BUBBLES
OR
BLISTERS.
CAUSED
BY SUDDEN
ACCE
LE
RAT ION.
CAN BE
CLEANED.
IDENTIFIED BY
WET BLACK DEP.
OS
ITS
ON
THE
INSULA TOR SHELL
BORE
ELECTRODES CAUSED BY
EXCESSIVE OIL
ENTERING
CO'ABUS.
TION
CHAMBER
THROUGH
WORN
RINGS
AND
PISTONS, EXCESSIVE
CLEARANCE
BETWEEN
VALVE
GUIDES AND STEMS, OR
WORN
OR
LOOSE
BEARINGS
.
CAN BE CLEANED
IF
ENGINE
IS NOT
REPAIRED,
USE
A HOTTER
PLUG.
IDENTIFIED BY LIGHT TAN
OR
GRAY DEPOSITS ON
THE
FIRING TIP.
CAN
i3E
CLEANED.
IDENTIFIED
BY A WHITE OR LIGHT
GRAY
INSULATOR
WITH
SMALL
BLACK
OR GRAY BROWN SPOTS
AND WITH BLUISH-BURNT APPEAR.
ANCE OF
ELECTRODES,
CAUSED
BY
ENGINE
OVERHEATING. WRONG
TYPE
OF
FUEL,
LOOSE
SPARK
PLUGS,
TOO HOT A PLUG, LOW
FUEL
PUMP PRESSURE OR INCOR.
RECT
IGNITION
TIMING. REPLACE
THE PLUG.
FIG. 6- Spark Plug Inspection Guide
20-5
IDENTIFIED
BY
DEPOSIT
BUILD
·UP CLOSING
GAP
BETWEEN ELECTRODES.
CAUSED BY OIL OR
CARBON
FOULING. IF
DEPOSITS ARE
NOT EXCESSIVE,
THE PLUG
CAN
BE CLEANED.
IDENTIF lED
BY SEVERELY
ERODED
OR WORN ELECTRODES.
CAUSED BY
NORMAL
WEAR.
SHOULD
BE
REPLACED.
PRE-IGNITION
IDENTIFIED BY MEL TED
ELECTRODES
AND
POSSIBLY
BLISTERED INSULATOR.
METALLIC DE POSITS ON
INSULATOR
INDICATE
ENGINE
DAMAGE.
CAUSED BY WRONG TYPE
OF FUEL,
INCORRECT
IGNITION
TIMING
OR ADVANCE, TOO
HOT
A PLUG, BURNT VALVES OR
ENGINE
OVERHEATING.
REPLACE
THE PLUG.
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