4B - Fuel System Leakdown Test (Fuel Pump and Regulator)

TOOLS REQUIRED
^ SA9127E-7 Fuel Flow/Pressure Adapter

CAUTION:
^ DO NOT ALLOW SMOKING OR THE USE OF OPEN FLAMES IN THE AREA WHERE WORK ON THE FUEL SYSTEM IS TAKING PLACE. ANYTIME WORK IS BEING DONE ON THE FUEL SYSTEM, DISCONNECT THE NEGATIVE BATTERY CABLE, EXCEPT FOR THOSE TESTS WHERE BATTERY VOLTAGE IS REQUIRED.
^ WHENEVER FUEL LINE FITTINGS ARE LOOSENED OR REMOVED, WRAP A SHOP CLOTH AROUND THE FITTING AND HAVE AN APPROVED CONTAINER AVAILABLE TO COLLECT ANY FUEL.

IMPORTANT: Battery must be at a minimum of 12 volts when performing any fuel system tests. Charge battery before proceeding if below 12 volts.

Fuel System Leakdown Test:

1. Relieve fuel system pressure. (Refer to "Fuel System Pressure Relief" procedure.) Service and Repair
2. Disconnect fuel feed line at fuel rail.




3. Connect Fuel Flow/Pressure Adapter SA9127E-7 into fuel feed line quick connect and make sure fitting is firmly latched.
4. Connect fuel pressure gauge to test adapter.
5. Connect fuel flow/pressure test adapter outlet end to a fuel return hose and place other end (of hose) into an approved container for fuel (or fill neck inlet).
6. Turn On/Off valve on fuel flow/pressure test adapter to Off.
7. Energize fuel pump for a minimum of 10 seconds. (Refer to "Energizing the Fuel Pump" procedure.) Procedures
7.1 Record fuel pressure.
7.2 Shut fuel pump Off.




7.3 Wait five minutes.
8. Record fuel pressure and subtract from pressure recorded in Step 3. (Repeat this procedure a minimum of two times.)
9. Compare pressure loss (decay) to published specification.
10. Refer to "Fuel System Diagnosis - Fuel Supply Chart" and use test result to make appropriate decision. Testing and Inspection