2
2-3 Fuel
b. Loosen the fuel tank cap to release any pressure from the fuel tank.
c. MAKE SURE the ignition is off. Locate the fuel system’s test valve or port.
Remove the protective cap.
WARNING:
The air conditioning test port looks similar to the fuel
system test port. DO NOT CONFUSE THESE PORTS. Refer
to your vehicle's service manual to ensure proper
connections.
d. Connect the tester to your vehicle’s fuel system:
■For Ford and some Chrysler vehicles: Install the Ford port adapter
on the throttle body or fuel rail test port, FINGER TIGHT ONLY, then
connect the gauge hose to the adapter.
■For GM and some Chrysler vehicles: Connect the gauge hose
directly to the test port, FINGER TIGHT ONLY.
e. Place bleed-off hose into an approved drain container. MAKE SURE the
hose remains in the container until testing is complete.
f. MAKE SURE all of the vehicle’s accessories (air conditioner, fan, radio,
defroster, lights, etc.) are turned off.
g. Turn ignition on and listen for fuel pump activation (most systems will
activate the fuel pump circuit for approximately two seconds when the
ignition is initially turned on to prime the fuel system). Check the test
setup and MAKE SURE no fuel leaks are present.
■If fuel leaks ARE present, turn off ignition IMMEDIATELY and repair
any leaks. BE SURE TO CLEAN UP FUEL SPILLS
IMMEDIATELY.
NOTE:
If your fuel system does not operate as described in step g, or if fuel
system is not operating properly, refer to the manufacturer’s service
manual for repair procedures or activation instructions.
h. When the fuel pump has been activated in step g, the fuel system is
pressurized. Verify the tester gauge indicates a system pressure which
corresponds with the specifications provided in your vehicle’s service
manual. If the fuel pressure is within vehicle manufacturer's specifications,
proceed to step j. If pressure is not within manufacturer's specifications,
proceed to step i.
i. Turn ignition off and follow the test and repair procedures in your vehicle's
service manual to correct the problem. After all necessary repairs have been
completed, return to step g.
j. Start and idle engine. RECHECK THE TEST SETUP FOR FUEL
LEAKS.
k. Read fuel pressure from the tester gauge. If the fuel pressure is within
vehicle manufacturer's specifications, proceed to step m. If pressure is not
within manufacturer's specifications, proceed to step l.
l. Turn ignition off and follow the test and repair procedures in your vehicle's
service manual to correct the problem. After all necessary repairs have been
completed, return to step j.
m. Turn ignition off.
n. MAKE SURE that the bleed-off hose is still routed to the drain container.
Press and hold the relief valve to bleed off system pressure. Hold the relief
valve until the tester gauge indicates 0 (see Figure 5).
o. Shake the bleed-off hose to ensure all residual fuel has been expelled.
