1978 Lincoln mark v wouldn't start?

[Mike]

me and my dad are working on a 78 lincoln mark v (its mine) and its runs super its got the 400m but one day we tried to start it and it it wouldn't fire only when you stopped cranking it it would pop (it had run the day before) so we let it sit thinking it was flooded then later we came back to it same thing so we pulled a spark plug and it would only spark once when we stopped cranking it so my dad fiddled with some wires near the battery and icm (by fiddled i'm mean moved around) and it fired we fiddled with the wires again and it still fired so we don't know what happened where just worried about it doing it again while where out driving it somewhere does any one know what happend Thanks