Waste utilization is found to be a challenging task all around the globe. Converting the waste into useful forms of energy is a significant landmark in meeting the demand of world energy requirement. Thus an attempt was made in this study to make use of Waste Cooking Oil (WCO) as a fuel to operate compression ignition engine effectively as it degrades both the environment and human health.WCO was collected form the hostel mess of the author institution. In the first phase of the study, a single cylinder water cooled diesel engine was developed and operated in a single fuel mode with neat diesel and WCO as fuel under various load condition. Engine was modified in the second phase of the work to operate in dual fuel mode with a low reactive fuel like ethanol as primary fuel. In this work ethanol was injected in the intake manifold using newly developed Electronic Primary Fuel Injection System (EPFIS). Experiments were conducted at 80% and 100% load condition with various ethanol energy shares. It was inferred that establishment of the EPFIS increased the brake thermal efficiency of engine fueled with WCO by 5% with additional benefit of drastic reduction in smoke and Oxides of Nitrogen (NOX) emission. Both Unburnt Hydrocarbon (UHC) and Carbon Monoxide (CO) emission were found to be marginally high with the injection system. Thus with the help of EPFIS,WCO can be used effectively in the part load as well as in full load condition in a compression ignition engine with UHC and CO reducing techniques in the future for producing clean and green energy.