5.6 Injectors

The injectors are nozzles which open under great pressure, about 130 bar (1849 psi). They are lubricated by the fuel that flows through them and do not usually fail mechanically. They can, however, become partially or totally clogged due to contaminated fuel. The first signs of injector trouble usually appear as knocking noises from one or more of the injectors or cylinders, engine overheating, loss of power, smoky black exhaust, increased fuel consumption, engine misfire, or excessive blue smoke during cold start. Other problems can cause similar symptoms. See 3. Troubleshooting before beginning repairs. Test injectors with an idle speed drop test, as described in 3.2 Diagnostic Testing.

The injectors can be disassembled for inspection and repair and parts are available, however, any time an injector is repaired its opening pressure must be readjusted by adding or subtracting internal shims.