Control of fuel injection apparatus for internal combustion engines

Claim 1

In a method of delivering a series of discrete, metered quantities of fuel for delivery to an engine comprising filling a metering chamber with fuel, admitting gas to the chamber at a pressure sufficient to displace the fuel from the chamber, displacing the fuel from the chamber by the admitted gas upon selective opening of a discharge port in communication with the chamber, and concontrolling the quantity of fuel displaceable by each admission of the gas to the chamber by adjusting the relative positions of the entry of the gas to and of the discharge of the fuel from the chamber between the positions, the improvement comprising delivering a base number of deliveries of discrete, metered quantities of fuel per engine cycle by generating a plurality of pulses per engine cycle, said pulses if not suppressed being capable of controlling the displacement of fuel from the chamber, suppressing a proportion of the pulses, and utilizing the pulses not suppressed to cause the said displacement of fuel from the chamber, and recognizing substantial engine load variations with resulting substantial engine fuel demand changes, such as acceleration of the engine, low engine temperature or cranking at starting, to deliver more fuel to the engine than could be rapidly accomplished by said control of the quantity of displaceable fuel by delivering additional metered quantities of fuel to said engine, until the control of the quantity of displaceable fuel becomes effective to meet the new engine load, by increasing the number of deliveries per engine cycle of the metered quantities of fuel above said base number of deliveries by including at least some of the pulses suppressed during delivery of said base number of deliveries to increase the number of pulses causing displacement of fuel from the chamber per engine cycle.