Sputter and then shutting off

[Mattcusdav]

I recently bought a 1990 300ZX non turbo and while i was driving down the highway at around 70 the car started to miss and sputter. It also did this at a stop light but not much. on the highway it would sputter and slow down in speed for about a mile and then it would run good for a mile, and then sputter again. I went as far as i could before she finally died. Had it towed to a shop and they couldn't find anything but said it could be something to do with overheating. I watch my gauges like crazy and it never showed any signs of over heating. I drove it home and around town for about an hour and it did fine. why the shop didn't fix it is beyond me. Im new to Z cars and would really appreciate any help.

[t.mcginley.jr]

Sounds like an air problem. Check the air intake and MAF to see whats going on. Does your car still have the stock airbox or a cone-shaped filter kind?

[Mattcusdav]

I have a cone style filter. Funny thing is, i drove it for almost 5 hours last week on the highway and it did fine. but then on a 10 minute trip to subway it acted up. It felt a little like it was idling a little low when i stopped at a light also. Its something i can live with, but i just don't want to break down in the middle of BFE again..