Bad idle problem

[96GSX]

Ok guys, I've searched all the forums, noone elses problem seems to be exactly like mine. My car idles really roughly, stalling to about 300 rpms at stoplights. I have adjusted the biss, it is in the right position. It idles fine while in park or neutral, and no matter how high the idle is in park, it drops down to about 3- 4 hundred as soon as I drop it in gear. When I go to start off, sometimes, it hesitates and will not go anywhere, no matter if I have the gas all the way down, until about 5 seconds. Its even worse when cold. I have to let it warm up all the way. I have adjusted the biss, taken off the mass air to see if it was clogged, air filter, intake hose, and no clogs. I visually checked for any holes or leaks in vaccum lines. Changed the plugs, wires, fuel injection cleaner, and alas, no fix. do u think it could be the fuel filter, help please.
thanks, Josh

 

[echo]

good possibility it is the problem. i was having problems like that. i replaced the fuel filter and it was all good. goto napa or advance and get a new fuel filter. it takes like 30 mins to install and that was because i didn't have the slightest clue what i was doing.