puffing black smoke...possible tuning problem

I finally got my 98 gsx on the road and it hesitates when revved in neutral and when driving, it happens consistently around 2-3k rpms, then it comes out of it and goes. Also in between shifts and heavy acceleration it blows black smoke. Before I bought the car there was a front mount intercooler and a test pipe on it, but it was taken off before I got it though. There is a Apexi AFC and a Greddy Profec-B installed, so I was thinking this was happening because the air/fuel intake may be off since there is a sidemount intercooler now. Anyone have any ideas? Thanks in advance for any help.

I would say that you have a tuning problem. I would start small to big...change plugs, oil change, fuel system cleaner...that kinda stuff. my next thought would be your ignition coils. had any problems with electrical stuff in your car? if so its probably that coil..$100.00 for precision tune to do it, part and all...if you have one where you are at. Then if that doesnt work then i would look at your timing. with this extra equipment, half there and half gone i would make sure that the previous owner did NOT mess with that timing. if so- take it to shop, unless you have the tools and knowledge and let someone tune it up. the car probably needs a good tune up anyways...it is 6 years old.

good luck

All that would be a good idea, but I what I meant was if it sounded like the AFC wasnt tuned properly.

I also noticed that when I drive under hard acceleration the car will die once it hits higher rpm's, any ideas why?

I am having the exact same problem with my GSX, i just put a six bolt in and am gettin poor excelleration and black all around my exhaust pipe, my timings right on and I have all new wires and plugs. I was wondering If it could be a prob with the turbo charger and i am gettin oil runing into my intake. anyone think this is logical, or is there some other explaination

i would say to both of you that you both have a tuning issue. check ur turbos, but i dont think they would be worn out yet, unless they are seized and are not spooling. then i would make sure that your computer is properly adjusted to that fuel curve...meaning check ur FMUs (fuel management unit) or whatever you have that is telling your car how much gas to pump. usually black smoke out of your tail pipe means that you are running rich (too much fuel) and white smoke means there is oil in the line.

hope this helps