Abstract: A fuel system for an engine (10) includes a fuel pump (13), a controller (14) which controls the operation of the fuel pump so that fuel is delivered to the engine at the required time and in the desired quantity, and a transducer (15) for supplying a demand signal to the controller. The system also includes a transducer (16) which provides signals in response to the passage of indicia on a wheel (12) driven by the engine. The system further comprises means for determining the indicia spacing errors and further means responsive to the generally sinusoidal fluctuation of engine speed which corrects the determined spacing. errors.

Abstract: A fuel system for an internal combustion engine includes a controller which controls the operation of an engine fuel pump. Signals are supplied to the controller by a transducer which is responsive to the passage of teeth formed on the periphery of a wheel which is mounted on the engine crankshaft. In order to generate an engine speed signal it is necessary to know the tooth spacing errors and these are determined from the transducer signals by using a cross-correlation technique to correct the transducer signals for interval variation due to cyclic fluctuation of engine speed following which the tooth spacing errors are calculated to be used in subsequent calculations of the engine speed.