Abstract: An electronic engine controller operates to control the phase angle of a variable position camshaft. The engine controller receives signals indicative of engine coolant temperature, aircharge temperature, throttle position, engine speed and camshaft position, and generates a camshaft position signal to a variable camshaft control actuator to alter the phase angle of the camshaft with respect to the engine crankshaft. The engine controller contains two tables which contain cam phase angles. The first table contains a plurality of values indexed by engine speed and engine aircharge and the second table contains a plurality of values indexed by engine speed and throttle position. The engine controller generates the camshaft position signal in one of three manners depending on the mode of engine operation. In a first mode of engine operation the camshaft position signal is generated as a function of engine coolant temperature and aircharge temperature.

Abstract: A VRS sensor detects the angular rotation of a variable position camshaft which rotates in a variable relationship to a crankshaft, and transmits a Variable Cam Timing/Cylinder IDentification signal, representative of the position of the angular rotation of the camshaft, to an electronic engine controller (EEC). A profile ignition pickup (PIP) sensor detects the rotation of the crankshaft and transmits a PIP signal, representative of the rotation of the crankshaft to the EEC. The EEC receives the VCT/CID signal and the PIP signal and identifies the position of a first firing cylinder in a predetermined sequence of cylinder firing and determines the angular position of the camshaft in relation to the crankshaft by detecting the varying time duration between VCT/CID signals and PIP signals.

Abstract: The amount of fuel injected in an engine with variable cam timing is more accurately reflective of engine operating conditions by accounting for the phase angle of the camshaft relative to the crankshaft in the calculation of the cylinder air charge. The cam phase angle for the existing engine speed is sensed and used in the calculation of a manifold filling coefficient which modifies the leakage compensated air flow data obtained from a mass air flow meter. A predicted final cylinder air charge is calculated based on the modified air charge from the manifold filling model and the required fuel for a desired air/fuel ratio is based on the calculated cylinder air charge.

Abstract: A method for controlling the amount of fuel mixture, including a first and second fuel of different volatility, to be supplied to an internal combustion engine includes calculating a base amount of fuel mixture needed to achieve a desired air to fuel ratio at a predetermined engine operating condition. Such a base amount of fuel mixture is modified as a function of the temperature of the internal combustion engine and is a function of the percentage of the first fuel.

Abstract: A method for controlling the amount of fuel mixture, including a first and a second fuel of different volumetric energy content, to be supplied to an internal combustion engine determines a desired air fuel ratio for the fuel mixture. The percentage of the first fuel in the fuel mixture is sensed and the desired air fuel ratios for the first and second fuels are determined. The desired air fuel ratio for the fuel mixture is determined as a function of the desired air fuel ratios for the first and second fuels.

Abstract: A method for controlling the amount of spark advance for an internal combustion engine using a fuel mixture having a first and a second fuel of different volatility and volumetric energy content. The percentage of the first fuel in the fuel mixture is sensed and a desired base spark advance is determined. The desired base spark advance is adjusted as a function of the percentage of the first fuel to achieve a desired engine operating condition.