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Injector Leak Test

CAUTION: Do not allow smoking or the use of open flames in the area where work on the fuel or EVAP 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. Lay shop towels on intake manifold and cam cover to collect any fuel. Make sure the injectors are positioned to prevent fuel from being sprayed onto the engine. Make sure that the injector retaining clips are properly installed.
NOTE: Gauge Bar Set (SA9127E) and Fuel Pressure/Flow Adapter (SA9127E-7) are required to perform this procedure. See Figure and Figure .
  1. Relieve fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE  under FUEL SYSTEMS.
  2. Connect Fuel Pressure/Flow Adapter to fuel pressure test port.
  3. Remove fuel rail assembly. Pull fuel rail back far enough so that nozzles of injectors are visible but still in ports. Attach fuel rail to intake manifold with wire.
  4. Connect Gauge Bar Set to Fuel Pressure/Flow Adapter.
  5. Wipe tips of fuel injectors free of any fuel or debris. Place a clean White towel directly under fuel injectors. Ensure towel lightly contacts each fuel injector tip.
  6. Connect scan tool and turn ignition On. Battery must be at a minimum of 12 volts when performing any fuel system test. Charge battery before proceeding if below 12 volts.
  7. Using scan tool, energize fuel pump.
  8. Observe fuel injector tips for leakage of fuel. If one or more of the White towels becomes wet with fuel after 5 minutes, replace faulty fuel injector. Pressure gauge reading should be about 40-50 psi (276-345 kPa).
  9. Test assembly a minimum of 2 times.
  10. Install bleed hose from Fuel Pressure/Flow Adapter into an approved container.
  11. Open valve to bleed system pressure.
  12. Remove Fuel Pressure/Flow Adapter from fuel pressure test port.
  13. Install fuel pressure test port cap. Replace plastic fuel line retainers whenever fuel supply lines are disconnected at fuel filter and fuel rail. Install new retainer into female portion of connection. Care must be taken to assure that locking tab is centered in window of female connection. Firmly press male and female portions together until a "click" is heard, then pull firmly back to confirm engagement.
  14. Lubricate injector "O" rings with clean engine oil and install fuel rail assembly.
  15. Start engine and check for leaks.
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