rpms drop quickly???

[91-gsx]

whenever i am coming to a stop or if i am stopped and i rev the engine, the cars rpms drop below 500rpms and it tries to die, my idle is set at 900. if i am coming to a stop quickly and push the clutch down to put it in neutral the rpms drop rapidly, probably because of my act flywheel, but they dip really low and the car dies twice today because i put it in neutral. i think it might be my alternator, because my rpms drop a lot when i roll the windows down, or if i turn on the lights, or if i turn on the rear defrost, and you could hear the fuel pump die a little as well when this happens, and of course the lights dim if they are on. if anybody has an idea please share your info.
thanks for the future replies

 

[kgtalon95]

I would do boot leak test, because a boost leak coul cause that

somtimes you Tps an wear down and cause weird stalling like that

Check your isc, if its not functioning well it will do the same thing.

I doubt its your act flywheel, although i've heard of people having this problem with the fidanza.

 

[Mackzero]

First thought in my mind is the little button on the Throttle body that senses that it is closed is not adjusted right. Look at the TB and see if that is it.