This thread is obviously very dead, just posting to hopefully help someone that may encounter the same problem as this comes up when you search for "Turn signals kill engine 280z". I was recently having this problem and have a thread tracking it down on ClassicZCar too.
The problem in my specific case was that the crimp for the White wire that provides power to the fusible link that protects the whole fuel pump, reverse lights, and turn signal system was corroded and fell apart when I peeled the electrical tape.
Anyway, I hope I can help someone find the source of their problems or at least bring this dead thread to a decent conclusion.
Also, at least for my '78 280z the fusible link block that appears to b in the front on the wiring diagram is actually in the rear.
