http://www.users.bigpond.com/INTERJECT/PROBLEM.HTM
Found it because my Vit would not idle at all... just kept on stalling. But had no troubles starting, or driving once revs were above 750 rpm. I was stressing that I'd fried the ECU somehow, or that I'd fecked up when I moved an unknown thing with vacuum lines coming out of it...
Turns out I hadn't tightened the terminal back onto the battery properly.

Anyway, hopefully this will help someone else out too.