New car: questions

[vtown661]

OK so i bought a new 98 GSX. The car had been sitting in the guys garage for 4 months and was modded poorly. It has a FMIC, SAFC II, vented BOV, Disconnected turbo timer, and an exhaust without a cat and thats all I can tell at this point. Now when I first got it it ran like crap but it still ran. When I got above 5000 RPM and let off the throttle the car would jerk quite a bit. I figured it was just a poor tuning job. So I drove it from the guys house after I bought it which is about 150 miles and I started to mess around with the SAFC (not really knowing what I was doing) and then the battery died before I could put the settings back to how they were. I bought a new battery and the idle was very low and would die if I didn't keep it going. Then if i went to rev it it would only go to about 3000 RPM and would stutter very bad and wouldn't go past that. So I figured it was the tuning and went back to try to put the settings back to what I could remember but for some reason I can't choose the low throttle points. I go to scroll over the lo throttle option and it just skips to the next option. I dont think it did this before. I'm also now thinking I might have a boost leak, are these signs of a boost leak? I haven't had the car running long enough to do the oil change or other basic mantainace and the same gas has been there for about 3 weeks. I know there are probably many possibilities of things that could be wrong with it but a few suggestions would be nice.

 

[brute]

Do everything you can maintenance-wise before you try to pick and choose what you think might be causing these problems. Look through the records (if any) that came with it. If you don't know the last time certain things have been done, go ahead and assume you'll be doing them in the next few weeks. Replace bad hoses, bad couplers, plugs, wires, and just do a general tune-up. After that, make a boost leak tester and do it. Just because you can't see a leak doesn't mean it doesn't exist. The only way to tell for sure is the properly-made tester.

 

[vtown661]

Are those signs of a boost leak though? Just so I know.