PRIOR TO TESTING FOLLOW THESE PRETEST PROCEDURES.
1. Read all safety precautions listed in this manual and the vehicles shop manual. Paying
close attention to air bag connections and precautions.
2. Do a thorough hands-on inspection of the fuel system. Look for fuel or vacuum line
leaks, cracked or loose electrical connections. If fuel leaks are present wipe them up
immediately.
3. Insure you have a fully charged battery and enough fuel to conduct this test.
4. Verify that the inertia switch on certain Ford/Lincoln/Mercury vehicles has not been
tripped. The inertia switch is designed to shutoff the fuel pump in the event of a collision.
This switch is typically mounted under the dash on the passenger side, or in the trunk.
5. Check that all fuel system fuses are good.
6. Verify that the fuel vapor recovery system, and gas cap are in good condition.
7. Locate the vacuum line which is attached to the fuel pressure regulator and remove it,
this line should be free of fuel, if fuel is observed the regulator has failed.
8. Once the inspection for the fuel pressure regulator is complete reinstall the vacuum line.
9. Test manifold vacuum to ensure it is within manufacturer’s specication. A typical
vacuum reading would be 18-20 in. at idle.
CAUTION: Be aware that fuel systems are UNDER PRESSURE AND HIGHLY
FLAMMABLE. Relieve system pressure before connecting the tester. Refer to your
vehicle’s service manual for those procedures. Systems without test ports require that fuel
lines be removed or disconnected. Be aware that these lines are also UNDER PRESSURE
AND HIGHLY FLAMMABLE. When removing the lines it could cause fuel to spray and/
or leakage onto hot engine parts. In addition to following all safety precautions, a basic
understanding of your fuel injection systems is necessary. Read your shop manual
thoroughly to prevent personal injury or damage to your vehicle.
1. Before connecting tester, relieve fuel system pressure. Refer to your vehicle’s service
manual for procedures. Loosen or remove cap from the fuel tank to relieve potential
tank pressure.
2. Ignition key must be in the off position.
3.
Locate the fuel system’s test port, and remove the protective cap. You’re A/C test port is similar
to the fuel system. Both have a protective cap and a Schrader valve inside. The low side
A/C port is typically larger than the fuel ports. Do not get these ports confuse. Refer to your
vehicle’s service manual to ensure proper connections. Wrap shop rags around tting when
connecting or disconnecting the tester. Have shop rags ready to clean up leaks or
spills.
4 5
4. Connect the tester to your vehicle’s fuel system test port.
- FORD, LINCOLN, MERCURY AND SOME CHRYSLER VEHICLES
Install the port adapter on the throttle body or fuel rail test port. Be sure the threads are
correct, it should thread on easily. Finger tight only, then connect the gauge hose to the
adapter. Clamp bleed-off hose into an approved drain container. Make sure the hose
remains in the container until testing is complete.
-GMC, CHEVROLET, BUICK, OLDSMOBILE, PONTIAC, CADILLAC AND SOME
CHRYSLER VEHICLES
The port adapter for the above models is permanently attached to the high pressure hose.
5. Connect the gauge hose directly to the test port, and nger tighten only. Clamp bleed-off
hose into an approved drain container. Make sure the hose remains in the container
until testing is complete.
6. Make sure all of the vehicle’s accessories including the A/C, fan, radio, defroster, lights,
etc. are all off.
7.
Turn your key to the on position, (KOEO), listen for the fuel pump to activate. Most injection
systems will activate the pump for about two seconds to pressurize the fuel system.
8. Check the setup connections for fuel leaks. If you have a fuel leak, turn off the ignition
immediately! Repair the leak and clean up the spilled fuel.
9.
If your fuel system does not activate as described above, turn ignition key off. Refer to the
manufacturer’s service manual for repair procedures or fuel pump activation instructions.
10. When you hear the fuel pump activate, the fuel system is pressurized. Verify by looking
at the pressure gauge, it should show a system pressure.
11. Check this against the information in the Specication section of your vehicle’s
service manual. If pressure is not within specications, turn ignition off. Follow the
repair procedures in the service manual. If fuel pressure is within manufacturer’s
specications, proceed to the next step.
12. Start the engine, (KOER), bring it to a normal idle. While warming recheck connections
for fuel leaks.
13.
Read the fuel pressure on the tester. If the fuel pressure is steady and within specications
for your vehicle, proceed to the next step. If pressure is not within specications, turn
ignition off and follow the test and repair procedures in your vehicle’s service manual. After
all necessary repairs have been completed, return to step 12 and retest.
14. When your test is complete and the desired pressure has been reached, record the
information and turn the ignition off. Typically in the back of a service manual there is a
“notes” section. This is a good place to record the detailed results.
15. Make sure the bleed-off hose is still clamped to the drain container.
16. Press and hold the pressure release valve to bleed off pressure still in the tester. Hold
the valve until the gauge indicates 0 PSI.
17. Jiggle the bleed-off hose to ensure all the fuel has been removed.
18. Use a shop towel to wrap around test port tting. This will aid in absorbing any residual
fuel, and guard against spray from potential pressure in the line.
19. Carefully unthread the tting from the port adapter. For Ford vehicles remove the
additional adapter from the vehicle’s test port. Replace protective cap on port tting.
20.
After the bleed off hose has drained completely remove it from the drain container. Store
the tester in a well-ventilated area to dry completely. Service life of the port adapter’s
O-rings can be prolonged by applying a protective coating oil to them before storing.
21. Verify that all fuel system components were reconnected. Start the engine, check for
leaks and repair as necessary. It might take a few extra cranks for the fuel system to
energize after delivery was interrupted.
• Never lay tools on vehicle battery. You may short the terminals together causing harm to
yourself, the tools or the battery.
• Never leave vehicle unattended while running tests.
• Always keep a re extinguisher suitable for fuel/electrical/chemical res handy.
• Always use extreme caution when working around the ignition coil, distributor cap,
ignition wires, and spark plugs. These components contain high voltage when the engine
is running.
• Complete all pre-testing checks before beginning fuel pressure testing.
• Always follow vehicle manufacturer’s warnings, cautions and service procedures.
CAUTION: Some vehicles are equipped with SRS Supplemental Restraint System,
safety air bags. You must follow vehicle service manual cautions when working around the
air bag components or wiring. If the cautions are not followed, the air bag may open up
unexpectedly, resulting in personal injury. Note that the air bag can still open up several
minutes after the ignition key is off, or even if the vehicle battery is disconnected because of
a special energy reserve module.
PRODUCT WARNINGS
OPERATION
OPERATION
To Next Page
Loading...