I have a ford falcon Forte 2002 series 3 Auto,and when i go up a hill it jolts and feels like the revs arnt going high enough... when i change the gears myself it feels ok but i changed the spark plugs in it and it was good for a while but started again, do you think i need to get the leads coming from the park plugs changed or would it be something else? i just don't want to spend $110 on getting new leads and it be something else.... please help.... Jayden.... 