Hi wondering if any of you can help i have 1.1 single point injection fiesta and it is running on 3 cylinders it seems to be starving 1 cylinder of fuel and eventually it will melt/burn the end of the spark plug , changing the spark plug helps for abit then it goes back to running on 3 could this be coilpack?ecu? ive changed the leads allready any help would be great thanks luke