BOLT-12 POINT HEAD 3S1307 - Caterpillar

Some of the Delphi, Bosch, and Stanadyne fuel injection pumps have a 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.
It is important that the electrical connections to the sender unit are connected correctly. If the cold start advance unit fails to operate correctly, engine damage may result because the engine timing will be fully advanced for normal engine operation.
The cold start advance unit is on the rear of the timing case on the left side of the engine.
Damage to the engine will occur if the engine is load tested at more than 80 percent of full load with the cold start advance unit disconnected.
Illustration 1 g00849690
Delphi DP200 fuel injection pump
(1) Engine stop solenoid
(2) 3 Amp wire
(3) Sending unit
(4) 3 Amp wire
(5) 6 Amp wire
(6) Fuel injection pump
(7) Cold start advance unit
(8) Start switch
Illustration 2 g00849700
Bosch fuel injection pump
(1) Fuel injection pump
(2) 3 Amp wire
(3) Engine stop solenoid
(4) Sending unit
(5) 3 Amp wire
(6) Cold start advance unit
(7) 6 Amp wire
(8) Start switch The cold start advance unit on the Delphi and the Bosch fuel injection pumps operate in a similar manner. As the engine begins to reach normal operating temperature, the cold start advance unit energizes. By energizing, the fuel injection pump timing is retarded to the correct timing for normal operation.
Damage to the engine will occur if the engine is load tested at more than 80 percent of full load with the cold start advance unit disconnected.
Illustration 3 g00849711
Stanadyne fuel injection pump
(1) Engine stop solenoid
(2) 3 Amp wire
(3) 6 Amp wire
(4) Fuel injection pump
(5) Cold start advance unit
(6) 3 Amp wire
(7) Sending unit
(8) Start switch The cold start advance unit on the Stanadyne fuel injection pump operates differently. As the engine begins to reach normal operating temperature, the cold start advance unit will de-energize. By de-energizing, the fuel injection pump timing is retarded to the correct timing for normal operation.Cold Starting Aid
Illustration 4 g00849717
Cold starting aid
(1) Connection for the advance lever to the pull rod
(2) Pull rod
(3) Electrical connection
(4) Element
(5) Advance lever
(6) Mounting bracket
(7) Battery Note: The advance lever (5) of the fuel injection pump is set at the factory in order to advance the injection timing when the engine is cold. The cold start advance unit must be energized, when the static timing of the fuel injection pump is checked.Note: Do not release the connection (1). The adjustment of the advance lever that is set in the factory will not be maintained.
Illustration 5 g00849720
(8) Locking plate
(9) Locking bolt Note: Before the crankshaft is turned or before the fuel injection pump is turned, loosen the locking bolt (9). Put the locking plate (8) under the locking bolt (9).Note: The crankshaft must not be moved, when the fuel injection pump is not on the engine. Movement of the crankshaft may result in damage to the timing case. If the crankshaft is moved, it may be necessary to reset the timing of the engine prior to the