Hoopster do you have a workshop manual for 103 ? After engine swop, did you check all earth points ,like gearbox to body earth strap .And check all earth points you can find. Vacuum is another item to look out for, as the little pipes run lots of items in the engine as well as gearbox if auto that is .And the rubber ellbow conections split that join them together . Rotor arm is another one . Can you try the old one back in as you said it had been replaced before..