Desperate Need of Help

[sweetjumper32]

I'm really in need of help with diagnosing my problem. Things began with a bad ISC, which I replaced. Car doesn't die now, but idle is still relatively bad when in park or neutral, RPM's rev between 1500-1800, if I lower my idle via BISS it'll die. Now, I can live with that. But the next thing I notice is that acceleration is poor, and at it's worst in the morning. I don't try to stomp on it in the morning, but just basic acceleration, really bogs, and sometimes feels like it wants to die. This is what I've recently been trying to figure out, but to no avail. And now, today another problem arises. My car is an automatic, and before, I could really feel the difference when overdrive was on or off, but starting today, there is absolutely no difference, I can play with the button all day under every speed and nothing. It feels like I'm always driving in OD. Somebody please help me ASAP. I have a 1995 GST, automatic, with no mods. Thanks, Michael

 

[sweetjumper32]

A little more information. Whatever is causing at least part of my problem, is also causing me to blow black smoke out the tailpipe every time I step on the gas. If I stomp on it, even in park, it sputters and sputters until a black cloud of smoke comes bellowing out the pipe. PLEASE HELP ME!