For GM/Chrysler Vehicles...
• Wrap a shop rag around fuel rail test
port in case a small amount of fuel drips
out while unscrewing test port adapt-
ers.
• Unscrew GM/Chrysler test port adapter
from fuel rail test port.
• Wrap a shop rag around GM/Chrysler
test port adapter so any fuel dripping
from gauge hose is absorbed.
• Remove bleed-off hose from approved
fuel container and hold gauge hose over
container so any remaining fuel will drip
into container.
14.Store shop rags in an approved con-
tainer so they cannot cause personal
injury or a hazardous situation.
15.Store Fuel Pressure Tester in a well
ventilated area where it cannot cause
personal injury or a hazardous situa-
tion.
• If your vehicles fuel system uses a fuel
pressure regulator without a vacuum
port than fuel pressure should remain
constant during both key-on-engine-off
and idle.
• Read fuel pressure from dial face.
• If fuel pressure is not within manufac-
turers specification, than service ve-
hicle according to vehicle service
manual.
• When repair is completed and idle fuel
pressure is now within manufacturers
specification, then proceed to Step 9.
• To safely disconnect the Fuel Pressure
Tester Kit from the fuel rail test port and
perform repairs at a later time, proceed
to Step 9.
9. Turn Ignition Key OFF.
10.Verify that 6 ft. bleed-off hose is still in
an approved container for fuel.
11.Fully DEPRESS and HOLD the pres-
sure relief button until dial face pointer
is resting on stop pin.
12.Shake bleed-off hose to make sure
that all fuel went into approved con-
tainer.
13.Remove gauge hose from fuel rail test
port.
For Ford/Lincoln/Mercury Vehicles...
• Wrap a shop rag around fuel rail test
port in case a small amount of fuel drips
out while unscrewing test port adapt-
ers.
• Unscrew GM/Chrysler test port adapter
from Ford test port adapter.
• Wrap a shop rag around GM/Chrysler
test port adapter so any fuel dripping
from gauge hose is absorbed.
• Remove bleed-off hose from approved
fuel container and hold gauge hose over
container so any remaining fuel will drip
into container.
• Unscrew Ford test port adapter from
fuel rail test port.
General Fuel Pressure
Diagnostics
Fuel pressure checking is an essential part
of fuel injection system troubleshooting. High
fuel pressure will make an engine run rich,
while low fuel pressure will make an engine
run lean or not at all.
Fuel pressure readings that are higher than
manufacturers specifications are generally
caused by a problem in the return line fuel
components. Conversely, fuel pressure read-
ings that are lower than manufacturers speci-
fications are generally caused by a problem
in the pressure line fuel components.
If fuel pressure readings are not within manu-
facturers specifications, then refer to a ve-
hicle service manual for step-by-step diag-
nostic procedures that will pinpoint the faulty
component for your specific vehicle.
Possible causes of high fuel pressure read-
ings are the following:
• Faulty fuel pressure regulator.
• Restriction in return line.
• Faulty fuel line couplings at fuel tank.
Possible causes of low fuel pressure read-
ings are the following:
• Clogged or restricted fuel filter.
• Restriction in pressure line.
• Faulty fuel pump.
• Faulty fuel pump relay.
• Bad fuel pump fuse.
• Faulty fuel pump wiring.
• Clogged or restricted fuel pump filter.
• Faulty fuel pressure regulator.
• Leaking fuel injectors.
• Faulty fuel line couplings at fuel tank.
Care and Maintenance
Apply a lightweight household oil to the rub-
ber “O” rings inside both the GM/Chrysler
and Ford test port adapters before each use.
®
ACTRON MANUFACTURING CO.
9999 Walford Avenue
Cleveland, Ohio 44102
