Perkins 900 Series Workshop Manual page 175

11
900 Series
Stanadyne fuel injection pump
The engines used on generator sets are fitted with the pin-timed Stanadyne fuel injection pump (D). The
electrical stop solenoid on these fuel pumps is fitted inside the governor housing. The earth connection (D1)
and the electrical supply connection (D2) are on top of the governor housing.
Caution: The low speed idle adjustment screw and the maximum no-load speed adjustment screw are sealed
with tamper proof screws in the factory. The adjustment must only be reset by persons authorised by Perkins
Engines company limited.
2
1
D
A0152
Atomisers
The atomisers, which are of the VCO (valve covered orifice) type, have nozzles with five holes. the atomisers
inject fuel in a very fine spray into the combustion chamber in the top of each piston. Each atomiser is fastened
to the cylinder head, either by a clamp or a gland nut. The atomisers are set in the factory, but they must be
checked in accordance with the preventive maintenance schedules. The pressure at which atomisers operate
can be adjusted by a change of shims fitted above the spring.
For details of the atomiser setting pressures for the engine, refer to "Atomiser service settings" on page 26.
Fuel system
Air is removed from the fuel pump through a leak-off pipe that returns fuel to the fuel tank, together with the
atomiser leak-off fuel. The pump is lubricated and cooled by the movement of fuel through the injection pump.
The pump has a mechanical governor to control the engine speed.
The pump has an electrical stop and an electrically operated cold start advance unit fitted.
Fuel from the tank leaves the pre-filter and then passes to the diaphragm type lift pump, which is driven by an
eccentric on the camshaft. Fuel leaves the lift pump under pressure and passes through a full flow filter to the
fuel injection pump.
The fuel injection pump increases the fuel pressure and supplies high-pressure fuel through small bore pipes
to the atomisers at the correct time and sequence. The atomisers inject fuel as a very fine spray into the
combustion chambers. Combustion occurs in a bowl in the piston crown.
A fuel leak-off rail is fitted to the top of each clamp type atomiser or the side of gland nut type atomisers. Excess
fuel, used to lubricate the internal parts of the atomiser, is returned to the fuel tank.
Workshop Manual, TPD 1345E, issue 3 165
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