The invention relates to supplying pilot fuel to the cylinders of a combustion engine. The invention comprises cylinder-specific pressure sensors (1) that are installed in the cylinders of the combustion engine, as well as a control unit (2). The control unit determines each cylinder's crankshaft angle at maximum pressure and the cylinders' average crankshaft angle at maximum pressure, and verifies whether the average crankshaft angle at maximum pressure is within a certain range of crankshaft angle variation. If the average crankshaft angle at maximum pressure is outside the range of variation, the duration of total pilot fuel injection into the engine is controlled. Furthermore, the differences between each cylinder's crankshaft angle at maximum pressure and the average crankshaft angle at maximum pressure are determined. The differences are compared with a certain range of difference variation, and the duration of fuel injection into a cylinder is controlled if the difference in an individual cylinder traverses the minimum or maximum limit of the range of difference variation.