Get the coil pack leads checked out or change them or best way find a family member or a friend that has the same car and swap around the leads and try if it works like that or the coil pack if its one of them change that but I for got to ask have you got any dashboard lights flashing or on ??? If there is it will cost you about £40 to £60 to find the fault from a garage. but if its got to do with the sparking it won't tell you if it the coil leads or the coil pack it's self but I think it many be coil but get a 2nd hand coil leads from a ford scrap yard for a £5 and try that first and see how it goes to save you on money and time . I hope you understand this lol.