As a major component of the fuel injector, injection nozzles must operate at peak efficiency. Once the nozzle spray is altered, engine performance and emission are adversely affected. At first sign of problem, find your nearest diesel calibration center and have them look to avoid irreparable damages.
At the first sign of an engine miss or loss of power, the nozzle should be checked, but only after other potential culprits, such as plugged fuel filter, have been found to be in proper working order.
Nozzle tips that are dirty and covered with carbon will not allow a proper spray pattern to be injected into the cylinder. Nozzles that are not clean may allow dripping, produce a distorted spray pattern or suffer excessive leak-off. In which case, it will adversely affect engine performance.