Crankcase emission control system - ’L’ series

Crankcase emission control system - ’L’ series

Gases from the crankcase are drawn into the inlet manifold to be burnt in the combustion chambers with the fuel mixture. The system provides effective emission control while the engine is running under all circumstances.

Crankcase gases are drawn from the camshaft cover into the turbocharger intake via a depression limiting valve (crankcase pressure limiting valve). The valve closes progressively as engine speed increases, so limiting the maximum depression in the crankcase.

Exhaust emission control

The engine management system provides accurately metered quantities of fuel to the combustion chambers to ensure the most efficient air to fuel ratio under all conditions of operation. A further improvement to combustion is made by measuring the oxygen content of the exhaust gases to enable the quantity of fuel injected to be varied maintaining the ratio necessary for efficient gas conversion by the catalytic converter.

The catalytic converter is situated between the exhaust front pipe and exhaust intermediate pipe. The catalytic converter reduces the emission of Carbon monoxide, oxides of nitrogen and Hydrocarbons released into the atmosphere. The active constituents of the converter are the precious metals Platinum and Rhodium.

The correct operation of the catalytic converter is dependent upon close control of the oxygen concentration in the exhaust gas entering the converter. The quantity of oxygen in the exhaust gas is determined by a heated oxygen sensor situated in the exhaust front pipe. The heated oxygen sensor provides the engine control module with a signal proportional to the oxygen content. The ECM can then determine whether any adjustment is required to the amount of fuel being injected to achieve the correct exhaust gas content, and implement the required changes.

CAUTION: Serious damage to the catalytic converter will occur if leaded fuel is used. The filler neck is designed to accommodate only unleaded fuel pump nozzles.