Ford THUNDERBIRD 1960 - 3-1 Fuel Sys. Maint.

TROUBLE DIAGNOSIS AND TESTING
Section Page
Fuel Tank and Lines. . . . 3-2
Fuel Pumps and Vacuum
Booster 3-2
Carburetor 3-3
2 Fuel Filter Maintenance.... 3-5
3 Carburetor In-Chassis
Adjustments 3-5
Ford Carburetor 3-5
Carter
Carburetor 3-7
4
Air Cleaners 3-8
FUEl. TANK AND LINES
Water and dirt that accumulates in
the fuel tank can
cause carburetor or
fuel pump
malfunction. Condensa
tion, which
is the greatest cause of
water entering
the fuel tank, is
formed by moisture in the air when
it strikes the cold walls of the fuel
tank.
If the accumulation of sediment in
the fuel pump sediment bowl is ex
cessive,
the fuel tank should be re
moved
and flushed and the line from
the fuel pump to the tank should be
blown
out.
FUEL PUMPS AND
VACUUM BOOSTER
Incorrect fuel pump pressure and
low
capacityare the two most likely
fuel pump troubles that
will affect
engine
performance. Low pressure
will cause
a lean mixture at high
speeds
and excessive pressure will
cause high fuel
consumptionand car
buretor flooding. Low capacity will
cause fuel starvation at high speeds.
TESTS
The tests are performed with the
fuel pump installed on the engine.
PRESSURE
TEST
1. On a 352 engine, disconnect
the fuel filter from the carburetor.
Install a pressure gauge and a T
fitting with a petcock between the
fuel filter and the carburetor.
2. On a 430 engine, disconnect
the fuel inlet line at the carburetor.
Install a pressure gauge and a T-fit
ting with a petcock between the fuel
inlet
line
fitting
and the
carburetor.
3. Vent
the system, by opening
the
petcock momentarily, before
taking
a pressure reading.
4. Operate the engine at the spe
cified rpm Part 3-5. After the pres
sure has stabilized, it should be with
in specifications Part 3-5.
S. If the pressure is
not to
specifi
cations, remove the fuel filter from
the system and tnke
another
pressure
test.
If the pressure is within specifica
tions with the fuel filter removed, the
fuel filter was restricted and a new
one should be installed.
If the pressure is not within specifi
cations with the fuel filter removed,
the fuel pump is defective.
CAPACITY TEST
Perform this test only when the fuel
pump pressure is within specifications.
1. Operate the engine at specified
rpm.
2.
Open the petcock and expel the
fuel into a suitable container. Ob
serve
the time to expel one pint. It
should be within specifications Part
3.5.
VACUUM BOOSTER TEST-
352 ENGINE
1. Connect a vacuum gauge to the
windshield wiper connection of the
pump.
2. Disconnect
the
pump to mani
fold line at the manifold and plug
the line.
3. Operate the engine at
specified
rpm and observe
the
vacuum
gauge.
The vacuum should be within specifi
cations
Part 3-5.
FUEL
PUMP TROUBLE DIAGNOSIS GUIDE
LOW FUEL PUMP
PRESSURE
Diaphragm stretched or leaking.
Fittings loose or cracked.
Spring weak.
Fuel line cracked or broken.
Rocker arm worn.
Valve improperly
seating.
Excessive clearance between rocker Dirt in
the fuel tank and/or lines.
arm, vacuum link, and fuel pump Fuel tank vent
restricted.
link. Diaphragm
ruptured.
HIGH FUEL PUMP
PRESSURE
Spring too strong
or
improper
spring.
FUEL PUMP LEAKS FUEL
Main body retaining screws loose. Threads on fittings stripped.
Diaphragm defective. Body cracked.
Fittings loose.
3-2
FUEL SYSTEM
MAINTENANCE
Section Page
1 Trouble Diagnosis and
Testing 3-2
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