System Description

CIS-E Fuel System:

CIS-E FUEL INJECTION SYSTEM
A mechanical hydraulic injection system provides the basis for the Bosch CIS-E Fuel Injection System. The mechanical portion of the CIS-E system consists of the Mixture Control Unit (Air Flow Sensor and Fuel Distributor combination), Diaphragm Pressure Regulator, Fuel Accumulator, Cold Start Valve, Fuel Injectors, two separate Fuel Pumps, Fuel Reservoir, Fuel Filter, Fuel Lines and the Fuel Tank. In addition, electrical controls such as the Differential Pressure Regulator have been added for increased flexibility to meet todays more stringent performance and exhaust emission requirements. Refer to COMPUTERIZED ENGINE CONTROLS for a detailed description of electronically controlled components.

The basic function of the CIS-E Fuel Injection System is to meter fuel to the engine dependent upon the quantity of air drawn in by the engine (which is the main actuating variable). The stream of air drawn in by the engine deflects the Air Flow Sensor, which in turn actuates the Fuel Distributor Control Plunger. Depending upon its position, the control plunger opens or closes the fuel-metering ports. The metering ports supply fuel through the pressure regulating valves to the individual fuel injectors. The CIS-E system also takes a number of additional engine operating data into account by means of sensors. The output signals from these sensors are processed by the CIS-E Control Unit that controls the Differential Pressure Regulator which adapts the injected fuel quantity to the various operating conditions. In the event of a major system malfunction, the CIS-E system operates solely with the basic function (CIS), and the driver then has a system at his disposal which provides a good limp-home capability when the engine is not performing at optimum efficiency.

FUEL SYSTEM COMPONENTS
These components are related to the fuel and air delivery portion of the CIS-E system and will be addressed in this section.

^ Accelerator Pedal
^ Air Cleaner
^ Air flow Sensor
^ CO Adjustment Screw
^ Cold Start Valve
^ CO Tap
^ Differential Pressure Regulator
^ Fuel Accumulator
^ Fuel Distributor
^ Fuel Filter
^ Fuel Injector Insert
^ Fuel Injectors
^ Fuel Pressure Regulator (Diaphragm)
^ Fuel Pump
^ Fuel Pump Relay
^ Fuel Reservoir
^ Fuel Return Line
^ Fuel Supply Line
^ Fuel Tank
^ Fuel Transfer Pump
^ Idle Air Bypass Screw
^ Idle Mixture
^ Idle Speed
^ Intake Air Hoses
^ Intake Manifold
^ Mixture Control Unit
^ Thermo Time Switch
^ Throttle Cable
^ Throttle Valve