Measure Fuel Pump Discharge Pressure; Measure Fuel Inlet Restriction - International VT 275 V6 Manual

Measure Fuel Pump Discharge Pressure

• Determine the ability of the fuel pump to
develop pressure by isolating the fuel
pump from the engine-mounted regulator.
• Remove the banjo bolt on the pressure line
at the secondary fuel filter and insert the
bolt through the back of the fitting so that
the bolt faces away from the engine. Install
the Fuel Pressure
(ZTSE4696) and tighten the bolt. Attach a
0-160 psi Fuel Pressure
(ZTSE4681) to the test adapter. The fuel
pump and its internal pressure regulator
are now isolated from the engine-mounted
fuel pressure regulator.
• Turn the key switch to the ON position and
measure the fuel pressure while the pump
is running. Pump discharge pressure
should reach 80 psi. If the pressure is low,
check for a plugged primary filter and/or
high pump inlet restriction.
F F U U E E L L I I N N L L E E T T
R R E E S S T T R R I I C C T T I I O O N N
A A D D A A P P T T E E R R
Test Adapter
Gauge
International
F F U U E E L L P P R R E E S S S S U U R R E E T T E E S S T T A A D D A A P P T T E E R R

Measure Fuel Inlet Restriction

• High inlet restriction can starve the suction
side of the fuel pump and cause low
fuel pressure.
• With the key switch OFF, remove the water
drain plug from the fuel pump. Install the
Fuel Inlet Restriction Adapter (ZTSE4698)
in place of the plug. Connect the 0-30
in/hg pressure gauge to the adapter with a
shut off valve in the OFF position between
the pump and the Fuel Pressure Gauge
(ZTSE4681).
• Turn the key switch ON. With the fuel
pump running, open the valve to the 0-30
in/hg pressure gauge and record the
restriction.
• If inlet restriction causes a gauge reading
of greater than 6 in/Hg, check the lines
from the fuel tank to the pump for restrictions.
® VT 275 V6 Engine
DIAGNOSTIC TESTS
95