Nissan Repair: 1984 300zx non-turbo, octane gas, million things

Question
i just purchased a 300zx. it ran fine for the first day  about 20 minutes after a filled it up with gas it started to stutter and acted like it was misfiring. i was wondering what could be the problem or if it requires 93 octane gas since i filled it with 87 octane.

Answer
based on your question, your answer could be a million things.  you've only had it a few days now?  let it run its new gas, there could be water in the tank or maybe there was old gas from sitting before it was sold to you.  run a few tanks of gas and enjoy your new car.  im thinking about getting a z31 myself.  lucky you :)  i would run high grade gas anyway, but im not sure about it being reccomended.  good luck with the car and enjoy the summer coming ahead.