Welcome!
The only time my car had a problem was my own fault, and letting the car overheat.
After I fixed that issue, It's been very reliable to me, even though I turbocharged it.
Just keep it well maintained and it should be good to you.
Due to their age, a lot of the seals are probably going to start leaking, so get ready for that.
If you need help with any of the procedures, consult the Factory Service Manual:
240sx-fsm-full-service-manuals-s13-s14- ... 11075.html
And one of our awesome members, vancouverbc, compiled a huge index on how-to guides that are in Nicoclub.
tutorials-t253879.html

Welcome to Nico!