Its sounds to me you are worrying about nothing mate, mine starts on 3 for a few seconds then clears up. I had a misfire on boost going to Croft but changed the plugs once i was there and has been fine ever since & still starts the same.

If your unsure its worth a check over with Stu & Kenny.

Oh and get that fookin Headgasket done, its been like that for weeks now