0327559 JOHNSON ORIFICE, High speed, No.71

Air Shutoff
The air shutoff uses a moving plate to block inlet air to the aftercooler. The engine stops because of the restricted air supply to the combustion chamber. The air shutoff only actuates for the following conditions:
The Emergency Stop button is pressed.
An overspeed shutdown occurs.Both of the air shutoffs must be reset before the engine can be restarted.
Illustration 1 g00751561
Reset knob for the air shutoff
To reset the air shutoff, turn the reset knob to the "OPEN" position.Ensure that both of the air shutoffs are reset.Cold Cylinder Cutout
Note: This feature can be enabled or disabled with Cat ET.The Cold Cylinder Cutout feature provides the following benefits:
Reduction of white smoke during cold starting
Reduction of the duration of advanced timing (cold mode)
Reduction of ether injectionThe ECM automatically turns off one electronic unit injector at a time during the following occurrences:
Cold start-up
Extended time at low idleThe ECM monitors the change of the fuel rack to determine if a cylinder is firing. If the cylinder is firing, the ECM activates the electronic unit injector. If the cylinder is not firing, the electronic unit injector remains deactivated. This process reduces white smoke.The following conditions must be met to activate the Cold Cylinder Cutout:
The Cold Cylinder Cutout parameter is programmed to "ENABLE".
The fuel rack is less than 13 mm (0.5 inch).
The jacket water coolant temperature is less than 63 °C (145 °F).The Cold Cylinder Cutout strategy is activated under either of the following conditions:
Ten seconds after the engine reaches the low idle rpm
Three seconds after ether injection is completedThe following conditions will deactivate the Cold Cylinder Cutout:
The Cold Cylinder Cutout parameter is programmed to "DISABLED".
The jacket water coolant temperature is more than 70 °C (158 °F).
A Cat ET is used for the cold cylinder cutout test.
The ether injection system is used.
The coolant temperature sensor has failed.
The engine is operating at a certain rpm when the Cold Cylinder Cutout is activated. If the engine rpm then varies by more than 50 rpm, the feature is deactivated for 3 seconds. A new engine speed is established when the feature is reactivated.
The engine is at low idle rpm for 10 seconds. If the engine speed is reduced by more than 50 rpm, the Cold Cylinder Cutout is deactivated for 30 seconds.
If the fuel rack is greater than 13 mm (0.5 inch), the Cold Cylinder Cutout is deactivated for one second.Droop
This feature enables an engine to share a load with other engines. If an engine is operating at high idle rpm and a load is applied, the engine rpm is reduced. The engine rpm is reduced as the load increases. This reduction in rpm is the droop. The droop can be programmed from zero to 10 percent. If the percent of droop is equal for two identical engines in a parallel configuration, the engines share the load equally.Ether Control
Note: Ether control is an optional feature.The ECM automatically injects ether into the air inlet manifold when the following conditions are met:
The engine rpm is between 75 and 400 rpm.
The jacket water coolant temperature is below 30 °C (86 °F).The duration of ether injection varies linearly with the jacket water coolant temperature. The duration of ether injection varies within the following range:
10 seconds at the maximum temperature of 30 °C (86 °F)
130 seconds at the minimum temperature of −40 °C (−40 °F)The longest duration of ether injection is 130 seconds even if the jacket water coolant temperature is less than −40 °C (−40 °F). See Illustration 2.
Illustration 2 g00749824
Temperature of the jacket water and duration of ether injection
(Y) Temperature in °C
(X) Time in secondsA momentary contact switch is installed on the control panel or the instrument panel. The momentary contact switch enables the operator to inject ether manually under the following conditions:
The momentary contact switch for the ether injection is activated.
The engine rpm is more than 75 rpm.
The jacket water coolant temperature is less than 30 °C (86 °F).Fuel Correction Factor
When the engine is shipped from the factory, an estimate of the engine fuel consumption is programmed into the ECM. The estimate is based on the engine performance specifications. The actual fuel consumption can be determined with a meter that measures the flow of the fuel. Customers are likely to find a slight difference between the estimate of fuel consumption that was programmed and the actual fuel consumption. The customer can use a Cat ET to program the ECM for the actual fuel consumption. A factory level security password is required to change this parameter.To program the ECM for the actual fuel consumption, change the Fuel Correction Factor that is already programmed into the ECM. The Fuel Correction Factor can be programmed in increments of 0.5 percent between 25 percent.Display of Engine Performance
Histogramming
The Cat ET can display the trends of the engine performance. The information can be used to improve the overall performance of the engine. The historical information is stored in a format that can be used to construct histograms. Data is available for the following parameters:
Engine rpm
Percent of engine load
Left side exhaust temperatures
Right side exhaust temperaturesIncrementing the Hours of the ECM
A new ECM that is installed on an engine can be programmed to display the correct total number of operating hours for that engine. A Cat ET and a factory level security password are required.Adjusting the Total Fuel Consumption for the ECM
A new ECM that is installed on an engine can be programmed to display the correct total fuel consumption for that engine. A Cat ET and a factory level security password are required.Data Link Features
Cat Data Link Flash
Flash - Flash is a method of downloading or programming electronic information.The CAT Data Link Flash provides the capability to flash the software for the engine control with the Cat Data Link.