Can't get results from a PAC sim

Hi,

I am trying to build up a dc-dc converter model, but I am having issues with PAC analysis. I put together a very simple modulator show below. I can get transient and PSS sims to work just fine. All of the waveforms look as expected. When I add PAC analysis I get 0V output on VOUT across the entire frequency range. I would expect to see some DC gain and then the double pole from the LC. I'm not sure if I am missing something simple or if this is the wrong type of analysis to use.