Help - kangarooing

[icb]

Car in factory yesterday and one of jobs was fitting Magnecor leads, but do not think it will be this. Was fine all way home but today as drive along feels like the limiter is kicking in but only 2-3000 revs. Then cutting out, and lurching all over the place. At idle revs all over the place. can anyone help as long way to C. Neils. Have a HP driving course booked for Bruntingthorpe Friday. Thanks a lot.