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Adapting the current liquid fuel injection technology to gaseous fuel presents some major technical issues. IMPCO Technologies, Inc. has committed to the development and commercialization of propane and natural gas fuel injection systems that use a unique injector design to precisely control the flow of fuel vapor. Considerable effort was focused on product validation tests including establishing gas flow test stand procedures. The gaseous injector that was developed can be used in propane or compressed natural gas applications. Operating inlet pressures are 18 psig and 60 psig for propane and CNG applications respectively. These injectors have distinct features that allow them to operate reliably over the life of the engine without lubrication from the fuel media.

THE APPLICATION OF HIGH SPEED. HIGHLY INTEGRATED DIGITAL MICROCONTROLLERS IN MODERN ANTI-LOCK SYSTEMS allows increased computational capabilities with the potential for improved control and performance over previously developed analog designs. The success of a microcontroller based ECU in demonstrating its performance capabilities lies in the basic control algorithm design and development. This paper will discuss basic algorithm design considerations and alternatives in digitally calculating basic parameters such as wheel and vehicle speeds, and deceleration. In addition, several microcontrollers are investigated and evaluated for suitability for anti-lock control application by review of their architecture and instruction sets.

Precise fuel pressure control is required by gaseous fuel injection systems to obtain high engine efficiency and low emissions. A preliminary design of next generation pressure regulators designated for alternative fuel injection systems was made by the Technology and Automotive OEM Division of IMPCO Technologies, Inc. The regulators are optimized for very precise fuel pressure control to satisfy the requirements for LPG injectors and CNG injectors. They also have the capacity to supply enough alternative fuel in gaseous phase for up to 10-liter engines without loss of performance. This paper presents this preliminary design concept analytically. Experimental results are also presented to validate the model. A more precise device change is underway to minimize dynamic pressure droop and hysteresisis.