2. INSPECTION AND ADJUSTMENT (5) Fuel injection nozzle pressure inspection Wear protective glasses when testing injection from the fuel injection valve. Never approach the injection nozzle portion with a hand. The oil jetting out from the nozzle is at a high pressure to cause loss of sight or injury if coming into careless contact with it. (a) Injection pressure measurement [NOTICE] As for the opening pressure of the brand-new fuel nozzle, about 0.5 MPa {5 kg/cm 2 } declines by the engine operation for about 5 hours because of the initial wear-out of a spring etc.
Therefore, adjust 0.5 MPa {5 kg/cm 2 } higher than the standard value of the above table when adjusting a new fuel nozzle of a spare part. Remove carbon deposit at the nozzle hole thor- oughly before measurement. 1) Connect the fuel injection valve to the high pressure pipe of the nozzle tester. 2) Operate the nozzle tester lever slowly and read the pressure at the moment when the fuel injection from the nozzle starts. 3) If the measured injection pressure is lower than the standard level, replace the pressure adjusting shim with a thicker one.
82E-5 – 98E-5 SERIES 2-23 Model Standard MPa {kg/cm2} 3D82E – 4D88E 21.6 – 22.6 {220 – 230} 4D94LE – 4D98E Thickness of pressure adjusting shims (mm) Injection pressure adjustment 0.13, 0.15, 0.18, 0.4, 0.5, 0.8 The injection pressure is increased by approx. 1.9 MPa {19 kg/cm2}, when the adjusting shim thickness is increased by 0.1 mm.