
172 LIGHT AND HEAVY VEHICLE TECHNOLOGY
the unit injectors, the unused fuel being returned to
the tank.
Advantages and disadvantages of unit injector systems
As compared with a conventional fuel injection system,
the unit injector system has the disadvantage of being
expensive to produce, since it involves the complication
of additional push-rods together with lower and
upper rockers to actuate the injectors from the engine
camshaft.
However, the system has the advantages (noted
earlier) of eliminating the necessity for high-pressure
fuel pipelines between the pump and injectors and of
combining all metering and injection functions. Other
advantage ...