
DIESEL FUEL INJECTION SYSTEMS 165
the axial sliding type (Figure 8.31). One end of this
valve has a stem on which is mounted a siidable toothed
rack of cylindrical form, the rack being engaged by a
pinion actuated from the pump control lever. Location
of the rack on the valve stem is performed by two
compression springs, the lighter one of the pair pro-
viding sensitive control during idling. The other end of
the valve is acted upon by fuel oil at transfer pressure
and, since this end of the valve is hollow up to an
undercut portion that is also cross-drilled, the fuel oil
must flow through the restriction offered by the valve
and metering por ...