Testing and Overhauling of fuel injector at regular intervals is necessary for the uninterrupted running of engines. Below you can find the step by step procedure for fuel injector testing.
Step by Step Procedure
> Stop the Engine on which work has to be carried out.
> Put MEN AT WORK tag at necessary positions
> Shut the air starting valve, fuel oil inlet & outlet valves and isolate the system.
> Let the lube oil priming pump run for half an hour after then stop it.( For main engine Exclude this step)
> Now, remove the high pressure pipe.
> Take out the fuel injector using its tool. Cover the hole with a cloth, so that nothing goes inside the unit
> Put it on the testing kit. Check the lifting pressure, atomization, pressure falling steadily, dripping of oil. If all are satisfactory and manufacturers overhauling time is not reached then no need to open up and overhaul . If not follow below steps
> Now, take out the injector from the testing kit, put in a diesel oil & clean it.
> Put the injector on the vice and tighten it.
> Loosen the lock nut of the injector.
> Now loosen the compression nut to release the spring pressure, then take out the spring.
> Open the cap nut and take out the needle and guide.
> Put the parts on the cleaned table.
> Check the condition of spring by dropping on the floor plate, it should jump and also check it by tightening in the vice and then releasing. The difference in the length, no cracks to be there.
> Check the visual needle, there shouldn’t be any scoring marks because it is made of Nitrite material.
> Try to insert the needle inside the guide at an angle of 45degree, the needle should be on its own weight.
> Check the size of injecting holes by using Go or No go gauge.
> If the go gauge is going then hole size is OK.
> If no go gauge goes, then it means the size has increased, then the nozzle needs to be changed.
> Now assemble the injector and do the lifting pressure setting on the test kit by adjusting the compression nut.
> Check the injector again for its lifting pressure, atomization, steady fall of pressure and dripping.
> If Everything showing fine put back fuel injector in place.