A vehicle includes an engine having a combustion cylinder, and at least one fuel injector configured to supply a number of fuel pulse to the cylinder. A controller is programmed to issue a first fuel pulse command to actuate the fuel injector allowing fuel to pass through the fuel injector as a first fuel mass. The controller is also programmed to monitor a voltage across the fuel injector, and determine a preliminary fuel injector opening magnitude based on a rate of change of voltage. The controller is further programmed to assign the preliminary fuel injector opening magnitude as a maximum fuel injector opening magnitude in response to the first fuel mass being greater than a quantity threshold. The controller is further programmed to apply a scaling factor to adjust a second fuel pulse command to normalize the maximum fuel injector opening magnitude value to a predetermined full open value.