Ford THUNDERBIRD 1960 - Page 9

1 -4 GROUP 1 - ENGINES AND EXHAUST SYSTEM
This
is
done
by operating the engine
with the
ignition wire removed from
one
spark plug at a time, until all
cylinders have been checked. Ground
the spark plug wire removed.
If the
engine speed changes when
a particular
cylinder
is
shorted out,
the
cylinder was delivering power
before being shorted out. If no
change in the engine
operation is
evident, the miss was caused by that
cylinder not
delivering power before
being shorted out. Check the:
IGNITION SYSTEM
If the miss
is isolated in a particu
lar cylinder,
perform
a
spark test on
the ignition lead of the
cylinder.
If a good
spark does not occur,
the trouble is in the
secondary cir
cuit of the system, check
the:
Spark plug wire.
Distributor cap.
If a good spark occurs, check
the
spark plug. If the spark plug is not
at
fault, a mechanical
component of the
engine is probably at fault.
ENGINE
Perform a compression test to de
termine which mechanical compo
nent of the engine is at fault.
MISSES
ERRATICALLY
AT ALL SPEEDS
EXHAUST SYSTEM
Exhaust gas control valve inoper
ative or sticking-352 engine.
Exhaust system restricted.
IGNITION SYSTtM
Breaker points not properly ad
justed.
Defective breaker points, con
denser, secondary wiring,
coil, or
spark plugs.
High tension leakage across the
coil, rotor, or distributor cap.
FUEL SYSTEM
Choke not operating properly.
Float setting incorrect.
Fuel inlet system not operating
properly.
Dirt or water in fuel lines, fuel
filter, or carburetor.
COOLING
SYSTEM
Check the cooling system for in
ternal
leakage and/or for a
condi
tion that prevents the engine from
reaching normal operating tempera-
ture.
ENGINE
Perform a compression test to de
termine which mechanical compo
nent of
the engine is at fault.
MISSES AT IDLE
ONLY
FUEL SYSTEM
Idle fuel mixture needles not prop
erly adjusted.
IGNITION SYSTEM
Defective coil, condenser, breaker
points, rotor, ignition wiring, or spark
plugs.
Excessive play in the distributor
shaft.
Worn distributor cam.
VACUUM BOOSTER PUMP
Leaking pump, lines, or fittings.
ENGINE
Perform a compression test to de
termine
which mechanical compo
nent of the engine is at fault.
MISSES AT HIGH
SPEED
ONLY
FUEL SYSTEM
Power valve clogged or damaged
-Ford carburetor.
Vacumeter not operating properly
-Carter carburetor.
Low or erratic
fuel pump pressure.
Fuel inlet
system not operating
properly.
Restricted fuel
filter.
COOLING SYSTEM
Engine
overheating.
ENGINE TROUBLE DIAGNOSIS GUIDE Continued
ENGINE RUNS,
BUT
MISSES Continued
FUEL
SYSTEM Fuel leakage at the
carburetor fuel
Engine idle speed set too low.
bowls.
Idle fuel system air bleeds or
fuel
ROUGH ENGINE IDLE
Idle
fuel
mixture needles not prop-
erly adjusted.
Float setting incorrect.
Air leaks betweenthe carburetor
and the manifold and/or fittings,
passages restricted.
Fuel bleeding from the accelerat
ing pump discharge nozzles.
Throttle plates not closing.
Improper secondary
throttle plate
stop
adjustment-Ford carburetor.
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