Fuel Pump Description; Fuel Pump Diagnosis And Testing; Fuel Pump Capacity (Volume) Test; Fuel Pump Assembly Removal And Installation - Ford VSG-411 Service Manual

3-03 Fuel System 3-03
FUEL PUMP
DESCRIPTION
A single action mechanical fuel pump is standard on this en-
gine. It is located on the right side of the engine and is driven by a
lobe on the camshaft.
The pump is permanently sealed and serviced by replacing the
entire unit (Figure 3).
4. Before taking a pressure reading operate the engine at the
specified idle rpm and vent the system into the container by
opening the hose restrictor momentarily.
5. Close the hose restrictor, allow the pressure to stabilize, and
note the reading.
FIG. 3 Permanently Sealed Fuel Pump
DIAGNOSIS AND TESTING
To determine that the fuel pump is in satisfactory operating
condition, tests for both fuel pump pressure and fuel pump capaci-
ty (volume) should be performed.
The tests are performed with the fuel pump installed on the
engine and the engine at normal operating temperature at idle
speed.
Before the tests, make sure the replaceable fuel filter has
been changed within the recommended maintenance mileage
interval. When in doubt, install a new filter.
PRESSURE TESTS
Refer to the fuel pump specification and note the fuel pump
pressure and capacity (volume) design tolerances.
1. Remove the air cleaner assembly. Disconnect the fuel inlet
line or the fuel filter at the carburetor. Use care to prevent
combustion due to fuel spillage.
2. Connect pressure gauge, restrictor and flexible hose (Figure 4)
between the fuel filter and carburetor.
NOTE: Inside diameter of smallest passage in test flow
circuit must not be smaller than .220.
3. Position the flexible fuel outlet hose and the restrictor so the
fuel can be discharged into graduated container (Figure 4).
FUEL OUTLET HOSE
PRESSURE GAUGE
URETOR FUEL INLET PORT
TO CARBURETOR
FUEL CONTAINER
ADAPTER FITTING
FIG. 4 Typical Fuel Pump Pressure and Capacity
Test Equipment
If the pump pressure is not within specifications with tem-
peratures normalized at idle speed and in neutral and the fuel lines
and filter are in satisfactory condition, the pump is worn or
damaged and should be replaced.
If the pump pressure is within specifications, perform the tests
for fuel capacity (volume).
CAPACITY (VOLUME) TEST
With the fuel pump pressure within specifications, test the
capacity (volume) as follows:
1. Operate the engine at the specified idle ' pm.
2. Open the hose restrictor and expel the fuel into the container
(Figure 4), while observing the time required to expel one
pint. Close the restrictor. One pint or more of fuel should be
expelled within the specified time limit (25 sec.).
If the pump volume is below specifications, repeat the test using
an auxiliary fuel supply and a new fuel filter. If the pump volume
meets specifications while using the auxiliary fuel supply, check
for a restriction in the fuel supply from the tank and for the tank not
venting properly.
REMOVAL AND INSTALLATION
FUEL PUMP ASSEMBLY
Removal
1. Disconnect the inlet and outlet lines at the fuel pump.
2. Remove the pump attaching screws, then remove the pump
and the gasket. Discard the gasket.
Installation
1. Remove all the gasket material from the mounting pad and
pump flange. Apply oil-resistant sealer to both sides of a new
gasket and to the threads on the attaching bolts.
2. Position the new gasket on the pump flange and hold the pump
in position against the mounting pad. Make sure the rocker
arm is riding on the camshaft eccentric. (Turn engine over
until the fuel pump eccentric is on the low side of the stroke.)
3. Press the pump tight against the pad, install the attaching
screws and alternately tighten them to specification.
4. Connect the fuel inlet and outlet lines.
5. Operate the engine and check for leaks.