SWITCH, PRESSURE 0966337 - Caterpillar

General Information
The C27 and C32 Machine Engines incorporate an electronic control system with electronically controlled fuel injection. These advancements in technology offer the following improvements over engines with mechanically operated fuel systems: enhanced engine efficiency, reduced smoke levels and lower exhaust emissions.The Electronic Unit Injection (EUI) fuel system eliminates many of the mechanical components that are traditionally used in the fuel injector assembly. The EUI system increases engine timing accuracy and air/fuel ratio control. The engine's timing advance is achieved by precise control of the fuel injection timing, while engine rpm is controlled by adjusting the injection duration.The engine is equipped with an Electronic Control Module (ECM) that is used to control engine operation. The ECM has built-in diagnostics in order to ensure that all of the components are operating properly. In the event of a system component failure, the ECM can send a signal to a warning lamp or a diagnostic lamp that will alert the operator to the condition. An electronic service tool can be used to read the numerical code of the faulty component or condition. Intermittent faults are logged and stored in the ECM memory.Starting the Engine
The ECM will automatically provide the correct amount of fuel that is necessary to start the engine. The throttle should not be held while the engine is being cranked. If the engine fails to start in 30 seconds, the starter switch should be released. The starting motor should be allowed to cool for two minutes before being used again.
Excessive ether (starting fluid) can cause piston and ring damage. Use ether for cold weather starting purposes only.
Cold Mode Operation
The ECM will set the cold start strategy when the coolant temperature is below 20 °C (68 °F).When the cold start strategy is activated, low idle rpm will be increased and engine power will be limited.Cold mode operation will be deactivated when any of the following conditions have been met:
Coolant temperature reaches 20 °C (68 °F).
The engine has been running for twelve minutes.Cold mode operation uses a modified control map, that is stored in the ECM, in order to adjust the fuel injection timing and the injection duration for white smoke cleanup. The engine will usually exit the cold mode operation before the walk-around inspection is completed. During cold mode operation, the engine will remain at the elevated rpm that has been specified for the engine.After the cold mode is completed, the engine should be operated at low rpm until normal operating temperature is reached. The engine will reach normal operating temperature faster when the engine is operated at low rpm and low power demand.Customer Specified Parameters
The engine is capable of being programmed for several customer specified parameters. For a brief explanation of each of the customer specified parameters, refer to the Operation and Maintenance Manual for your engine.