1993 240SX Fastback - Advance Problem?

[HSVDrifting]

One of my friends came over with a timing light and we tried to time the 240. We had it close, but he said I have a problem with my advance (I think it's because it idles rather erratically?). I've looked in my FSM and it mentions nothing about an advance.

He gave me the example of one of his celicas. He said he just had to disconnect a vacuum tube and plug it to disable his. How do you disable it on a KA24DE?

I know this my be kind of a newbie question, so thanks in advance for your help.

- Collin