I think your ignition systems is not strong enough to jump that large of a gap. This may be due to a number of things, worn wires, cap/rotor, coil.
Try regapping them to .9mm (.035in??) and see if that is any better, if not, then back down to .8mm.
What year/model is the car? How many miles? What are the age/condition of the other secondary ignition parts? From other posts, 1mm is possible and is recommended for smoother idle, but that is taking into consideration that the other components are new or in good working order.
Hope this helps.