8KENR6912
Systems Operation Section
The fuel injection pump sends fuel through the high
pressure fuel lines to each of the fuel injectors. The
fuel injector sprays the fuel into the cylinder. Fuel that
is not injected flows through the fuel return line to the
top of the fuel filter, back to the fuel tank.
The engine must not be started until the fuel injection
pump is full of fuel that is free of air. The fuel injection
pump requires fuel for lubrication. The precision parts
of the pump are easily damaged without lubrication.
The fuel system must be primed when any of the
following conditions occur:
•The fuel filter is changed.
•The fuel line is removed.
•The fuel injection pump is removed.
Fuel System Components
Fuel Injection Pump
General Operation
The fuel injection pump is a pressurized system
that is totally enclosed. The pump sends the correct
amount of fuel under high pressure at the correct time
through the fuel injectors to the individual cylinders.
The fuel injection pump regulates the amount of fuel
that is delivered to the fuel injectors. This action
controls the engine rpm by the governor setting or
the position of the throttle control.
The fuel lines to the fuel injectors are equal lengths.
This ensures evenpressureandcorrect injection
timing at each fuel injector.
During operation, extra fuel is used as coolant and
lubricant for moving parts of the pump. The extra fuel
is circulated through the pump housing. The extra
fuel is then returned to the fuel tank.
The Delphi DP210 and DP310 fuel injection pumps
must be serviced by an authorized Delphi technician.
For repair information, contact your Perkins
distributor.
High idle and low idle of the fuel injection pump are
factory set. Idle adjustments can not be made to the
fuel pump. The Delphi DP310 fuel injection pump has
a boost control. The Delphi DP210 and DP310 fuel
injection pumps have an engine stop solenoid and a
feature that vents air from the pump.
The Delphi DP210 and DP310 fuel injection pumps
haveacoldstartingaid.Thecoldstartingaid
advances the timing of the pump when the engine is
cold. The cold starting aid is electrically operated.
Cold Start Advance Unit
The cold start advance unit holds the timing of the
fuelinjectionpumpinanadvancepositionwhenthe
engine is cold.
The coolant switch for the cold start advance unit is
on the water temperature regulator housing on the
left side of the engine.
When the engine is cold, the sender unit is
energized in order to advance the fuel injection
pump timing for the cold start operation. When the
correct temperature is achieved the sender unit is
de-energized and the fuel injection pump timing is
returned to the normal operating position.
If the switch fails in the closed position, the engine
will run with advanced fuel injection timing. The
engine will have higher cylinder pressure and engine
damage may result.
If the switch fails in the open position the engine
will run with the fuel injection timing in the normal
operating position. The engine will be more difficult
to start. When the engine is cold the engine might
emit white smoke.
This document has been printed from SPI². Not for Resale
