Hello. I have had a 1984 300ZX non-turbo for 2.5 years and have been having problems lately and now it has become so bad that I can't drive it. About a year ago I was driving to school in the morning and about 1.5 miles from my house my car died, no sputtering, nothing, it completely shut off and wouldn't start; it would crank over but not even try to start. I came back after school and it started and ran rough for a bit but then ran normal. It did this at intervals of about two weeks three times after that, always at the same distance from the house. After that the frequency increased so I took it to the dealership and they said they couldn't find anything wrong. I had a mechanic put in a new ignition switch and some fuel components to see if that pacified it but it didn't. I checked the relays, fuses, and fusible links but found nothing. I took it back to the dealership and they said that the distributor had weak resistance and the timing belt was loose. I recently put in a new timing belt and distributor but the problem persists, it will start fine most of the time and at random intervals it will just shut down.
Any input would be greatly appreciated.