93 p71 problem

hey all,
started a few weeks ago my 93 cv (145 k ) on a cold start would run rough almost like it was missing, even jerk and stutter a bit when in gear. but after it ran for a few minutes it was fine. then one day it died on me sittin in park, every thing went dead no click from starter or anything .dash light were lit and batt light stayed on . popped hood and puched all plug wires, nothin, jiggled batt cables, nothin for some reason i pushed on the alt wire on the top of alt then she started fine. went about a week perfect. then started doing it again. now while driving it jerks hard almost like tranny outta gear but its the engine because my tach drops to zero while it does it. and at time slowing down to a stop sign it'll die. sometimes messin with that wire it'll start. but lately it wont do the trick any more. the conection looks clean and like its making good connection. should i rip the covering off the wires follow it and put on a new wire? would that one little wire kill the engine but still give me dash lights but not allow it to start? wondering if anyone else has had this, or if i have a another problem