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A bi-fuel (Compressed Natural Gas [CNG] and gasoline) pickup truck has been developed using the Ford Alternative Fuel Qualified Vehicle Modifier (QVM) process. The base vehicle's 4.9L engine has been specially modified for improved durability on gaseous fuels. The base vehicle's configuration has been designed for conversion to bi-fuel CNG operation. A complete CNG fuel system has been designed and qualified, including fuel tanks, fuel system, and electrical interface. The completed vehicle has been safety and emission certified, demonstrating CARB Low Emission Vehicle (LEV) emissions in MY95. This paper details the design objectives, development process, CNG components, and integration of the two fuel systems.

Fuel injection systems are pressurized to 100 kPa and higher. As injection pressures increase there is also an increase in the potential for flow induced pressure pulsations. Fuel flow instabilities, especially at cold temperatures, can adversely affect driveability. Issues of noise and driveability caused by fuel flow ripple in fuel injection systems can be resolved by using the correct pulse damper. For comparing pulse dampers and for calibration purposes, it is important that standard methods are used to measure performance. This paper presents a standard method for measuring fuel system pulse damper attenuation at low frequencies. The paper presents fundamental acoustic considerations, reviews the performance required for pulse dampers in fuel systems, reveals a standard test method, shows attenuation data obtained with the standard procedure and analyzes the test results. The data includes repeatability and damper population performance information.

About 10 years ago in the US, an automotive OEM consortium formed the Oxygenated Fuels Task Force which in turn created the SAE Cooperative Research Project Group 2 to develop a simple rational method for qualifying materials. At that time the focus was Methanol/Gasoline blends. This work resulted in SAE J1681, Gasoline/Methanol Mixtures for Materials Testing. Recently this document was rewritten to make it the single, worldwide, generic source for fuel system test fluids. The paper will describe the rationale for selecting the fuel surrogate fluids and why this new SAE standard should replace all existing test fuel or test fluid standards for fuel system materials testing.