Perkins Injector Refit Fall 2004:

     Fun With Injectors
Rebuilding injectors is a normal part of diesel engine maintenance. It is not difficult and on most engines has no impact on engine timing. The timing is defined by the orientation of the injector pump when it is installed. The last time the injectors were serviced was in 1998 when I had the injector pump rebuilt. In 1998 a couple of the injectors had minor issues with the spray pattern. Since then I have approximately 1000 hours on the engine and several types of fuel.

To remove the injectors first remove the injector pipes which run between the injector pump and the individual injectors. The injector pipes should be removed completely as bending an injector pipe will require replacing it and these are expensive components. The following pictures show each of the injector pipes, numbered with #1 being the pipe going to the injector closest to the header tank and #4 being the pipe going to the injector closest to the transmission. The ends are covered with aluminum foil to prevent contamination getting into the pipes while removed from the engine. (Note that each of these images can be selected and get a high resolution image)

 Perkins 4-107 Injector Pipe #1

Injector Pipe #1

Perkins Injector Pipe #2

Injector Pipe #2

Perkins Injector Pipe #3

Injector Pipe #3

Perkins Injector Pipe #4

Injector Pipe #4

 

The second step is to remove the fuel return tube which runs across the top of the injectors.

The third step is to remove the retaining nuts on either side of each injector.

Finally the injectors are removed by rotating the injector back and forth around it's axis while lightly pulling up on the injector body. Take care to rotate the injector by it's base as the upper section of the injector can back out from the base.

The injector looks like this:

Looking closely at the injector tip shows a considerable amount of information about how the engine is doing. In the case of my Perkins they are all look very similar:

Basically as each of the injectors came out each one showed no deposits and a soft black shading which suggests that each of the cylinders is burning fuel well and that there are most likely not any significant issues with the rings or valves. (i.e. neither is leaking oil into the combustion chamber)

None the less, I sent the injectors and injector feed pipes off to Dumas Injector in Long Beach for testing and servicing. Their turn around is about one day and so I should be able to reinstall the injectors next weekend.