i was just given an 86 300zx turbo about a week ago finally got a chance to go and start it the other day. car would not start so i assumed it was the battery cause the cars been sitting for about five years. didnt have access to a charger so a friend pulled out the jumpers and tried starting it while i was replacing the door handle (had to have keys made). my friend then tell me that the car is smoking, i get up and look in the engine compartment and they tell me no inside the car. come to find out it was the ecu. i found a replacement but was hoping someone may be able to shed some light on why it may have don this before replacing it.