PLATE 5097590 - Caterpillar

Fuel Heaters
Fuel heaters prevent the plugging of the fuel filters in cold weather. This plugging is called waxing. The engine will not dissipate enough heat in order to prevent waxing. Heaters that are not thermostatically controlled can heat the fuel in excess of 65 °C (149 °F). High fuel temperatures will reduce the engine performance, the transfer pump check valve, and the system reliability.Note: Never use fuel heaters that do not have some type of temperature regulator that is incorporated into the system.Fuel System Electronic Control Circuit
The injection pump, the fuel lines, and the nozzles that are used in the traditional Caterpillar diesel engines have been replaced with a mechanically actuated electronically controlled unit injector in each cylinder. A solenoid on each injector controls the amount of fuel that is delivered by the injector. The ECM sends a signal to each injector solenoid in order to provide complete control of the engine.Electronic Controls
The electronic control system consists of two main components:
ECM
Personality moduleThe ECM is the computer. The personality module is the software for the computer. The personality module contains the operating maps. The operating maps define the following characteristics of the engine:
Horsepower
Torque curves
Engine speed
Other characteristicsThe ECM determines a desired rpm that is based on the following criteria:
Accelerator pedal position
Diagnostic codes
Status of the switch for the Power Take-Off (PTO)
Vehicle speedThe vehicle must be in a cruise mode or a PTO mode in order to use the last two criteria.The ECM maintains the desired engine speed by sensing the actual engine rpm. The ECM calculates the amount of fuel that needs to be injected in order to achieve the desired rpm.Fuel Injection
This engine uses an injection system control that allows variable control of the injector's spray pattern during the duration of fuel injection into the cylinder. A pilot injection takes place in order to start fuel combustion in the cylinder. When the pilot injection has been completed, the fuel injection delivery is then controlled by the ECM in order to optimize the combustion efficiency for the current operating conditions. This requires a new camshaft with a modified injector lobe.The ECM controls the amount of the fuel that is injected by varying the signals to the electronic unit injectors. The electronic unit injectors will inject fuel only if the electronic unit injector solenoid is energized. The ECM sends 120 VDC to the solenoid in order to energize the solenoid. By controlling the timing of the 120 volt signal, the ECM can control injection timing. By controlling the duration of the 120 volt signal, the ECM can control the injected fuel amount.The ECM sets certain limits on the amount of fuel that can be injected. The FRC fuel position is a limit that is based on boost pressure in order to control the air/fuel mixture for the emission control. When the ECM senses an increase in the boost pressure, the ECM increases the FRC fuel position. The rated fuel position is a limit that is based on the horsepower rating of the