Emission Control Systems — General Description (Opel Vectra A)

Multec System

1. The fuel vapor extraction system is designed to reduce the amount of unburned hydrocarbons released into the atmosphere.

2. The fuel filler cap is sealed and a carbon canister is mounted under the right front fender to collect petrol vapours from the tank when the car is not in use. These vapours are stored there and when the engine is started they are released into the intake air duct and from there into the engine where they are burned. The canister regulating valve (top) is opened by a vacuum pipe connected to the throttle body on the C16 NZ, C16 NZ2 and C18 NZ engines. On the XI6 SZ engines the valve is opened by the electronics of the purge valve mounted on the camshaft housing.

Motronic system

3. The system is similar to that described in Section 4B, except that the canister is controlled by the fuel injection/ignition system unit via the vent valve in the fuel tank. To ensure that the engine runs properly when cold and/or idling and to protect the catalytic converter from a rich mixture, the valve does not open until the engine is running at part load or full load. The valve coil begins to energize and stored vapor passes into the intake air duct.

4. The procedures for removing and installing the carbon filter are described in Chapter 11.

5. On C20 NE engines, the ventilation valve is installed above the injectors of cylinders 2 and 4. To remove it, disconnect the negative cable from the battery and the electrical wiring from the valve, then disconnect the two ventilation hoses, marking their position. Remove the valve from the mounting bracket, or unscrew the bracket together with the valve.



6. On C20 XE engines, the vent valve is located on the left end of the engine, below the end of the fuel injector wiring harness housing (see illustration). The removal and installation procedures are described in the previous paragraph.

Simtec System

7. For information see. "General description" in Section 4B. Note that "AIR" is an abbreviation for "Air Injection Reactor" (toxicity neutralization system).