Method for operating a fuel injection system for a combustion engine

The method involves carrying out fuel withdrawal from a pressure storage device (13) in a measuring interval and avoiding fuel withdrawal from the pressure storage device in another measuring interval. An operating variable of a pressure regulation device is determined in the both measuring intervals. The fuel quantity withdrawn in the former measuring interval is determined from the determined operating variable of the pressure regulation device, particularly from a difference of the determined operating variable. Independent claims are included for the following: (1) a method for manufacturing an injection valve; and (2) a computer program for use in a control or regulating device of an internal combustion engine for the execution of operating method.