Now-a-days, it is a common problem that occurs in the fuel injection pump is “Air lock or Diesel block”. It is difficult criteria to find out where the air lock occurs in the vehicle. This air lock can cause blockage in the nozzle holes (incase of partly blocked nozzle, the angle of spray of nozzle would be differed. For example: if the angle of spray is 30 degree it is varied to 45 degree). If the angle of spray of nozzle differs fuel does not burn completely. It also causes starting trouble in the vehicle. The choking of the diesel strainer also occurs due this air lock. There is an easy methodology to identify and overcome the air lock problems. This paper explains how the air lock occurs in the fuel injection pump and how to identify the air lock and rectify it.

Keywords : Air Lock, Fuel Pump, Strainer.