User Manual

Oil that is drawn from the sump is pressurized to the lubrication system oil pressure by the engine oil pump. Oil
flows from the engine oil pump through the engine oil cooler, through the engine oil filter, and then to the main
oil gallery. A separate circuit from the main oil gallery directs a portion of the lubrication oil in order to supply
the unit injector hydraulic pump. A steel tube on the left side of the engine connects the main oil gallery with
the inlet port of the unit injector hydraulic pump. The connection point is the top port of the manifold on the
engine side cover. Oil flows into the inlet port of the unit injector hydraulic pump and the oil fills the pump
reservoir. The pump reservoir provides oil to the unit injector hydraulic pump during start-up. Also, the pump
reservoir provides oil to the unit injector hydraulic pump until the engine oil pump can increase pressure.
Oil from the pump reservoir is pressurized in the unit injector hydraulic pump and the oil is pushed out of the
outlet port of the pump under high pressure. Oil then flows from the outlet port of the unit injector hydraulic
pump to the high pressure oil passage in the cylinder head. Actuation oil that is under high pressure flows from
the unit injector hydraulic pump through the cylinder head to all of the injectors. Oil is contained in the high
pressure oil passage until the oil is used by the unit injectors. Oil that has been exhausted by the unit injectors is
expelled under the valve covers. This oil returns to the crankcase through oil drain holes in the cylinder head.
Actuation Oil Pressure Control
(12) Control valve solenoid
(13) Poppet valve
(14) Armature
(15) Actuator spring
(16) Sliding sleeve
(17) Actuator piston
(18) Eccentric drive plate
(19) Idler
(20) Spill port
(21) Pump outlet ports
(22) Drive gear
(23) Check valve
(24) Piston