BOSCH Cis (Lambda) System: Description
The Bosch Continuous Injection System is a hydraulic-type fuel injection system which uses an air flow sensor (mechanically connected to a hydraulic valve) to control injection quantity.
The Lambda system is a feedback control capable of measuring air/fuel ratios and correcting them constantly. The combination of the two systems makes it possible to obtain economy and performance, while minimizing exhaust emissions. See Fig 1.
The system consists of the mixture control unit (air-flow sensor and fuel distributor), control pressure regulator, auxiliary air valve, cold start valve, thermo-time switch, injector nozzles, fuel pump, filter, oxygen sensor, electronic control unit, frequency valve, and catalytic converter. Some models use additional components, such as a thermo-vacuum valve, hot start pulse relay, or a constant idle speed control system.