Needing some help guys. I have a 1989 dodge shelby dakota v8. It has only 15k original miles. Just last week took it to a shop and they said the computer needed replaced because the cap rotor and I think hollow point switch was rusted and fried it. Well they replaced the computer and now the tach is acting up. While driving its fine, but as soon as it is given a little gas the tach jumps all the way up and truck runs rough. Was told the tach signals are controlled by coils and they could be rusted out. where can i find these coils?