1990-93 VW Passat
CIS-E is a hydro-mechanical, continuous-flow fuel-injection system. Fuel injection is not timed, nor is fuel injected in pulses. The injectors deliver fuel continuously whenever the engine is running, and fuel metering depends on precise control of fuel pressure. The main components are the airflow sensor, the fuel distributor, the fuel injectors, the differential pressure regulator, and electronic control unit. The ECU controls the fuel injection, idle speed, ignition and emission controls by analyzing the engine coolant temperature, engine speed, throttle position, and oxygen content in the exhaust.