Abstract: The invention provides an improvement over conventional engine controls by directly measuring fuel volatility, and using this measured value to adjust the engine air/fuel ratio during engine start and initial operation. Engine startability and initial operation are improved as compared to conventional engine control systems by compensating the engine air/fuel ratio during engine start and initial engine operation, using a direct measurement of the fuel volatility.

Abstract: An engine control system comprising: a mass air flow sensor in an air intake path for a vehicle engine and providing a first input signal indicative of mass air flow through the mass air flow sensor; an air pump unit having an inlet coupled between the mass air flow sensor and the vehicle engine and an outlet coupled in a path of exhaust from the vehicle engine, wherein the air pump unit is responsive to a first control command; a mass air flow estimator responsive to a set of measured engine parameters for providing a second input signal indicative of mass air flow into the intake manifold; and a control unit including a first control command generator responsive to the first and second input signals to provide the first control command responsive to a difference between the first and second input signals, wherein the difference between the first and second input signals represents an estimate of the instantaneous secondary air flow.

Abstract: Internal combustion engine ignition timing control for timing combustion events of an air-fuel mixture in engine cylinders in response to cylinder mean effective pressure feedback information. Cylinder mean effective pressure information is provided through monitoring of variation in ion content in cylinder combustion plasma through ionization current variation measurement and integration. Ion content variation monitoring is carried out at varying ignition timing angles and ignition timing is driven toward timing associated with a minimum ion content variation corresponding to a preferred ignition timing associated with maximum combustion efficiency.