The performance of the recently proposed modification of the sliding pair-wise intersection of confidence intervals (SPICI) method for the instantaneous frequency (IF) estimation, based on the pseudo Wigner-Ville distribution (PWVD) with an adaptive window width, is analyzed on a noisy monocomponent nonlinear frequency modulated (FM) signal. The modified SPICI method is an extension of the original SPICI method with an additional threshold criterion combined with the amount of overlap between the current and the previous confidence interval relative to the current interval length. When compared to its original version, the modified SPICI approach results in up to 39% improvement in the IF estimation accuracy in terms of the mean absolute error (MAE), and up to 72% improvement in terms of the mean squared error (MSE).