Tests and Adjustments
1. After the parts are cleaned and inspected the fuel valve is assembled as per the manufacturer’s instructions and thereafter tested for function and performance.
2. The assembled fuel valve is installed on the test stand and after purging the pipe line the manual handle is operated in quick succession. The nozzle should start discharging with a sharp crackling noise at the set pressure. The pressure at which the injector is supposed to fire depends upon the manufacturer’s engine design but normally is between 250 to 350 kg/cm2 with an allowance of plus or minus 10 kg/cm2.
3. In case the lifting pressure is not correct, it can be adjusted by the adjusting screw.
4. The spray characteristics should be satisfactory and as per the manufacturers advice.
5. All the holes of the injector should be firing and can be checked by a torch light or a filter paper can be folded as a cone and then the injector tested. The holes on the filter paper will show the number of holes firing. In this procedure you must be careful as the high pressure spray can enter the skin and is toxic for us.
6. The spray angle should be as stated by the manufacturer. The atomization of the fuel should take place and solid spray should not come out.
7. Clean diesel oil should be used for the testing purpose.
8. In the case that the fuel valve is dripping the needle guide should be taken out and repaired.