FUEL SYSTEM7-38 TNV DI Service ManualFuel InjectorsTesting of Fuel Injectors1. Thoroughly clean the fuel injector nozzle usingclean diesel fuel and a brass wire brush.2. Visually inspect the fuel injectors and nozzleprotectors for deposits or damage. Clean, repairor replace as necessary.Note: For testing the fuel injector using aninjection nozzle tester. Operate the testerfollowing the information provided by thetester manufacturer. Use clean, filteredfuel or FIE calibration fluid for the test.3. Using the correct adapter, connect a fuelinjector to a nozzle tester. Aim the fuel injectorinto a suitable container to catch the fuel spray.Figure 7-524. Pump the operating lever of the tester slowly,observing the pressure reading at the pointwhere the fuel injector begins spraying fuel(Figure 7-52).See Figure 7-55 for injector ID location.See Test and Adjustment Specifications onpage 7-12 for correct pressure readings.Note: The opening pressure of a new fuelinjector will be approximately 725 psi(5 MPa; 51 kgf/cm 2 ) higher than one thathas been operated for five hours orlonger.CAUTIONNever use a steel wire brush to cleanfuel injectors. Damage to the nozzle andother components is likely to result.0000172enA WARNING• Never inject fuel toward you. Since thefuel is injected at high pressure fromthe nozzle, it may penetrate the skin,resulting in injury.• Never inject fuel toward a fire source.Atomized fuel is highly flammable andmay cause a fire or burn skin.0000028enA CAUTIONFLYING OBJECT HAZARD!• ALWAYS wear eye protection whenservicing the engine and when usingcompressed air or high-pressurewater. Dust, flying debris, compressedair, pressurized water or steam mayinjure your eyes.• Failure to comply may result in minoror moderate injury.0000003en-GAGE-P-ON OFFOFF
