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A new method to estimate instantaneous A/F ratio and use the estimation as a feedback signal to control AFR during cold transients, before the oxygen sensor is functional, has been realized by a on-board PCM for a vehicle with a 4.6L, V8, PFI engine [4, 6]. Different AFRs cause variations in flame propagation, causing fluctuations in the effective torque. When a known AFR disturbance is induced into an engine system, a corresponding crankshaft angular velocity fluctuation can be detected. A variable derived from this physical phenomenon can be used to characterize the problem. The optimal fuel perturbation signal is designed by a relaxation concept, and the system model is determined by employing a dual-direction screening multivariate stepwise regression analysis. The estimated AFR is used by the PCM in a closed loop control to correct the fuel during cold transients.

As part of the P2000 hydrogen fueled internal combustion engine (H2ICE) vehicle program, an engine dynamometer research project was conducted in order to systematically investigate the unique hydrogen related combustion characteristics cited in the literature. These characteristics include pre-ignition, NOx emissions formation and control, volumetric efficiency of gaseous fuel injection and related power density, thermal efficiency, and combustion control. To undertake this study, several dedicated, hydrogen-fueled spark ignition engines (compression ratios: 10, 12.5, 14.5 and 15.3:1) were designed and built. Engine dynamometer development testing was conducted at the Ford Research Laboratory and the University of California at Riverside. This engine dynamometer work also provided the mapping data and control strategy needed to develop the engine in the P2000 vehicle.

The search for fuel efficient engines that also offer good performance and fuel economy at moderate cost prompted the development of the Split Port Induction (SPI) concept at Ford Motor Company. Ford has upgraded two families of 2-valve engines, the 2.0L CVH 14 and the 3.8L and 4.2L Essex V6's, with the Split Port Induction concept. SPI offers an improved WOT torque curve, better part load dilution tolerance for fuel economy and superior idle combustion stability. This is accomplished by dividing the intake port into two passages and inserting an intake manifold runner control (IMRC) valve into the secondary passage. The opening of this valve determines the level of in-cylinder charge turbulence and volumetric efficiency according to engine operating conditions. The development of the concept and the improvements resulting from its application to these engines will be described and discussed.