The inspirals of stellar-mass compact objects into supermassive black holesconstitute some of the most important sources for LISA. Detection of thesesources using fully coherent matched filtering is computationally intractable,so alternative approaches are required. In a previous paper (Wen L and Gair J R2005 Class. Quantum Grav. 22 S445), we outlined a detection method basedon looking for excess power in a time–frequency spectrogram of the LISA data.The performance of the algorithm was assessed using a single ‘typical’ trialwaveform and approximations to the noise statistics. In this paper we presentresults of Monte Carlo simulations of the search noise statistics and examine itsperformance in detecting a wider range of trialwaveforms. We showthat typicalextreme mass ratio inspirals can be detected at distances of up to 1–3 Gpc,depending on the source parameters. We also discuss some remaining issueswith the technique and possible ways in which the algorithm can be improved.