car stalling, won't start back up. chronic issue.

[Nerfdude]

tonight my car died. here's what happens. whenever you stick in the clutch, the rpm's drop down below 500 rpm's and bounce up to around 600. sometimes, the car stalls and you can restart it. DO NOT STOP READING THIS AND TELL ME IT'S THE IAA VALVE, THE AIV VALVE, OR SOME OTHER ANSWER LIKE THAT JUST YET. however, sometimes it stalls and won't start again. when i try to start it, the starter cranks but the car doesn't start. i've checked the wires for spark, and THERE IS NONE. what the HELL is up with that?
3 months ago i replaced the ignition control unit. the car stopped dropping and DYING, but still dropped pretty low. 2 months ago, it started dying again. i bought an ignition coil. it stopped dropping and dying. just now, it died again. i cleaned out the throttle body and the sensor tube thing that hooks to the airbox with carb cleaner. didn't help. so, my question: what the hell is wrong with the car? it's driving me insane, and i'm almost ready to give nissan the finger and go find myself a 2nd gen rx7 or a mkIII supra or something... maybe thier problems are less annoying...

also, when i searched for answers to this crap, i've seen people referring to the thing with reeds as both the IAA and the AIV. also, people have been calling the hard-to-reach thing both the AIV and IAA. so can someone please distinguish which is which, which does what, and what the acronyms stand for?