The effect of variation in injection pressure and Injection timing on the performance and exhaust emission characteristics of a direct injection, naturally aspirated Diesel engine operating on Diesel and Diesel-Biodiesel Blends were studied. A three-way factorial design consisting of four levels of injection pressure (150,210, 265,320 bar), four levels of injection timing (190 btdc, 21.50 btdc, 260 btdc, and 30.50 btdc) and five different fuel types (D100, B10, B20, B40, and B60) were employed in this test. The experimental analysis shows that when operating with Linseed Oil Methyl Ester-Diesel blends, we could increase the injection pressure by about 25% over the normal value of 20MPa. The engine performance and exhaust emission characteristics of the engine operating on the ester fuels at advanced injection timing were better than when operating at increased injection pressure. As for environmental protection, the replacement requires advancing the injection timing in order to achieve a pollution level lower than that produced by diesel fuel. This injection timing must be advanced ~ 22% (260 btdc to 31.50 btdc) from the setting provided by the manufacturer to obtain the best smoke results with the ester fuels. Engine performance deteriorated in an attempt to retarding the injection timing and reduced injection pressure.