Page Number - 11
Fuel Pressure Test Kit
MODEL MV5546
Form 824129
Connect the pressure gauge to the other end of the ex-
9.
tended pressure hose.
Before proceeding:
10.
Double check the connections.
•
Route and secure the clear pressure relief hose into
•
an approved gasoline container
Route any hoses away from any rotating engine com-
•
ponents, belts, fans, and hot exhaust components
Remove the fuel spillage rags
•
Reconnect components such as PCV tubes, wiring
•
harnesses, vacuum tubes, etc., that were disconnect-
ed to gain access to the fuel line connection.
Re-enable the fuel pump (if previously disabled), and
11.
cycle the ignition switch to the ON position for a brief time,
and then back OFF. Do not start the engine.
On most vehicles, cycling the ignition ON and OFF will allow
the fuel pump to run briefly, and prime the system. After cycling
the ignition, check all fuel connections for leaks. If all fitting
connections are secure, the installation is complete and the
fuel pressure tester is ready to be used for diagnostic tests.
Test Procedures
Key On, Engine Off Test
Cycle the ignition switch to the ON position. Verify that the
pressure gauge indicated a system pressure within the specifi
-
cation provided by the manufacturer. If the reading is within the
manufacturer’s specification, proceed to the “Key On, Engine
On” test. If it is not, follow the test and repair procedures out-
line in the vehicles service manual to correct the problem.
Key On, Engine On Test
Complete all the steps indicated in the Key On, Engine Off
1.
test
Start the car and idle the engine. Recheck the test setup
2.
for fuel leaks
Read the fuel pressure from the gauge
3.
Turn the car off when the readings have been made
4.
Disconnecting the Fuel Pressure Tester
When vehicle testing is completed, turn off engine and
1.
relieve pressure on the fuel system by pressing the
pressure relief valve located on the stem of the pressure
gauge. Watch the pressure gauge readings and fuel being
released through the small clear hose to the collecting
container.
Make sure that the pressure relief hose is routed and
secured into an approved gasoline fuel container.
Place shop towels under the connections to capture any
2.
fuel that may spill out when the hoses are disconnected.
WARNING: After testing a returnless fuel system, use
extreme caution when disconnecting the hoses to the
fuel rail. If the engine is hot, releasing the pressure from
a returnless fuel system will cause the fuel to boil in the
fuel rail. Even though the pressure has been released, the
boiling fuel will cause it to build up again once the hose is
clamped. To reduce the risk of fuel spray it is best to allow
the engine to cool before disconnecting the hose. Other-
wise, use the pressure relief valve to relieve the pressure
just before removal. Try to keep a shop towel wrapped
around the connection to catch any fuel spray.
Disconnect the Schrader port adapter or the inline pres
-
3.
sure test assembly.
Remove the fuel rail adapters if applicable
4.
Reconnect the fuel lines
5.
