PIPE 1100019 - Caterpillar

Illustration 1 g02264199
Typical example
Fuel from the tank (A) leaves the primary fuel filter (2) and then passes to the diaphragm type fuel transfer pump (1). The fuel transfer pump (1) is driven by an eccentric on the camshaft. Fuel leaves the fuel transfer pump (1) under pressure and passes through the secondary fuel filter (3) to the fuel injection pump (5). The secondary fuel filter (3) is a twin filter.Extra fuel is circulated through the injection pump (5). The extra fuel is then returned to the fuel tank.A fuel heater or cooler may be installed between the filter head and filter canister.The fuel injection pump (5) sends fuel through the fuel injection lines (4) to each of the fuel injection nozzles (7). The fuel injection lines (4) to the fuel injection nozzles (7) are equal lengths. This ensures even pressure and correct injection timing at each fuel injection nozzle (7). The fuel injection nozzle (7) sprays the fuel into the cylinder. Fuel that is not injected flows through the fuel return line (6) to the top of the secondary fuel filter. The fuel then flows back to the fuel tank (B).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
Illustration 2 g01352237
Typical example
(1) Fuel injection pump
(2) Locking screw
(3) Washer 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 injection nozzles to the individual cylinders. The fuel injection pump regulates the amount of fuel that is delivered to the fuel injection nozzles. This action controls the engine rpm by the governor setting or the position of the throttle control.The Delphi DP310 fuel injection pump must be serviced by an authorized Delphi technician. For repair information, contact your Caterpillar dealer. High idle and low idle of the fuel injection pump are factory set. Idle adjustments cannot be made to the fuel pump. The fuel injection pump has a boost control and an engine stop solenoid. The Delphi DP310 fuel injection pump has a feature that vents air from the pump.The fuel injection pump has a cold starting aid. The cold starting aid 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 fuel injection pump in an advance position when the engine is cold.The coolant switch for the cold start advance unit is on the rear of the timing case on the left side of the engine.When the engine is cold, the sender unit is energized in order to advance the fuel