ENGINE PROBLEM on s14! HELP!

[96s14]

Hi I have a 96 S14. I used to thing my car had a really good engine since in last 2 years I been kinda pushing it but it never turn down on me.... except recently, there're a problem1) my car can't idle well in special occasion.1) where I start the car.. rpm will go really low..then the car shakes...looks like it's gonna die (sometimes it really dies) ...then the rpm will bounce back and forth...and evetually steady at 700 rmp. 2) when I stoped the car.. the rpm will again bounce between 400 and 800 for 3 seconds..then steady at 700..sometimes the engine just dies..

HELP!!!

[NISTECH]

http://www.nissaninfiniticlub....shtml

[NISTECH]

http://www.nissaninfiniticlub....+drop

[notmisfit]

That 2nd thread had alot of people with similar issues, it still seemed like no one had a solid solution to the problem. If I am missing it by all means please point it out, I read through the thread 2 times already (had done the intake manifold/injector cleaner route long ago, this did nothing to solve the issue for me at least)