In diesel engines, the most important parameter affecting the combustion performance is the injection advance. Since the injection advance directly affects the combustion quality, it also directly affects the outputs, such as ignition delay, in-cylinder pressure, fuel consumption, and emission values. Therefore, setting the advance angle correctly is exceedingly significant for the optimum operation of the engine in all conditions. In this study, a single-cylinder diesel engine with a mechanical fuel system was converted to a common rail fuel system by revising its fuel system. Experiments were carried out with the converted engine at a constant speed (1850 rpm), at different loads (3–4.5–6–7.5–9 Nm), and at different advance angles (10, 12, 14, 16, 18°). In the experiments, engine performance and emission (exhaust, vibration, noise) data were examined. When the cylinder pressure data is evaluated, the maximum in-cylinder pressure approaches the top dead point in parallel with the increase in the advance angle. Specific fuel consumption occurred at a minimum advance angle of 10° under all load conditions. In exhaust emissions, minimum values at 10° advance angle were obtained for all emissions except for oxygen emissions. Vibration emissions were reduced by 6% at a 10° advancing angle compared to 18° advancing angle at 3 Nm load. It was determined that noise emissions decreased by 1.76% in the same experimental parameters. When all data are evaluated, the optimum advance angle for the revised fuel system has been determined as 10°.