please i need help with a ka24de (i think its the distributor)

[niceassfd]

hi everyone! i just bought a 96 240sx for my little bro as a graduation gift. the dude i bought it from said that the car idles weird because he replaced the distributor. he said the car ran fine until the distributor went out and when he installed the new one he didn't know he had to match everything.
i looked all over zilvia and found numerous threads, but i don't know if my situation is similar. i found links in the threads to

http://www.ka-t.org/tech/ and
http://www.240sx.org/faq/articles/timing101.htm

i am going to try to do those proceedures again with my little bro, but i wanna see if you guys got more inputs.

i also read that it could also be the fuel filter, spark plugs, or vacume lines.

any input will be greatly appreciated, i want to try to get this running fine so my bro can start driving it to school his senior year. thanks in advance!

allen