Delay main page load to show pop-up first

Hi, thanks for the great plugin. We have created full-screen a pop-up which acts as an intro page on homepage only. The delay is set to 0 but for a small fraction of time the main page is displayed and then the pop-up hits. Is there a way to make the pop-up load absolute first or to delay main page so the first second is just the pop-up without home page apearing for a fraction.

Thanks