First off i drive a 1985 300zx with 140,000 miles on it.

I had a problem a couple weeks ago where my car would bog out when i gave it gas. I brought it to my mechanics and they hooked up a fuel pressure tester to find there was low fuel pressure. They put a new fuel pressure regulator in and it seemed to work for a day or so. A couple days after i had what seemed to be the same problem but it was stalling out at idol which had never happened before. I belive this issue could be something to do with the spark now and the spark plug amplifier was very hot and is starting to melt and crack. If anyone could help me on what they think it might be i would appreciate it greatly.

Welcome to the site, and congratulations on driving a Z car.

There is a great site devoted solely to your model Z, the Z31, that you will want to check out:

http://www.z31.com/

or this one

http://www.thumper300zx.com/

I'm not trying to push you away from here, but you will find much more information about your car there than here, since this site deals mainly with the earlier years, though there are several z31 owners here.