Legacy Vehicle Fuel System Testing with Intermediate Ethanol Blends

The goal of this project is to make a high-level compatibility assessment of legacy vehicle fuel system components to intermediate blends of gasoline and ethanol, specifically focusing on vehicles produced in the mid-1990s. These vehicles were designed before ethanol was a common gasoline component; therefore, their tolerance to higher concentrations of ethanol is not certain. This research project compared the effects of two blends of ethanol fuel on legacy fuel system components. An ethanol gasoline blend of 10% by volume ethanol (E10) was used for the control group, and a 17% ethanol by volume (E17) blend was used for the test group. The fuel systems tested comprised a fuel sending unit with pump, a fuel rail and integrated pressure regulator, and the fuel injectors. These systems were assembled into test rigs and operated to simulate the exposure received while driving. Specifically, the fuel pumps were cycled off and on and the fuel injectors were cycled with varying pulse widths during endurance testing. The performance characteristics of the systems and components were measured and periodic physical inspections were conducted to determine whether E17 fuel would lead to unusual degradation due to material incompatibilities. The aging testing lasted a minimum of 1,000 hours, which nominally simulates about 25,000–30,000 miles of highway vehicle travel. Fuel system components from three common mid-1990s vintage vehicle models were studied. Parts were chosen for the following vehicle/engine families: 1995-6 Ford Taurus with 3.0L-V6-2V VIN U engine (without flex-fuel), 1993-6 General Motors 3.1L-V6-2V VIN M engine (various vehicle models), and 1995 Toyota Camry with 3.0L-V6-4V 1MZ-FE engine.