Fuel Delivery and Air Induction: Description and Operation

General CIS-Turbo Fuel And Computer Control System Schematic:

The CIS-TURBO engine control system is a mechanical, continuous injection system which is electronically controlled. The system is based on the Bosch K-Jetronic fuel injection system. Like the CIS-MOTRONIC system, a single electronic control unit (ECU) is used to control the fuel delivery and ignition systems. The main difference between the CIS-TURBO control system and other electronically controlled CIS systems (CIS MOTRONIC AND CIS-EIII) is the digital rather than analog control of the fuel system. The digital control system can be easily identified by the absence of a "Differential Pressure Regulator" (or pressure actuator as it is sometimes called) on the fuel distributor. Two other devices are used instead, an "Oxygen Sensor Frequency Valve" (or "Lambda" valve), and a "Warm-Up" or "Control Pressure Regulator" (mounted on the engine block). The ECU monitors information from various engine sensors and uses this information, compared with information stored in its memory, to precisely control the fuel and ignition systems for lower exhaust emissions, better fuel economy and better engine performance, under all operating conditions.

The primary fuel and intake system components are covered here. For information about the computer, controlled devices and information sensors, refer to Computers and Control Systems.