Focus ST? :D
Did some working on the white car...
Took apart the rocker cover to sort out the cutting out while the car is driving and more recently wanting to stall when acc is pressed.
Found oilly plugs and oil on two of the black arms of the coilpack.
Rocker cover off cleaned up and and resealed leaving over night, plugs cleaned but will probably buy new ones.
Hopefully that fixes it all.