1.. Use the search button... If you would have, you would not have asked that question
2. Try running a can of BG44k. You should be able to get it from here..
http://www.infinitipartsusa.com/ or if you have a close by Oreilly Auto Parts, thy should have it too.
3. There is no way around the injectors, its either bad or good. and $125 per injector is good. Last time i heard it was $160. And if you need those.. call joe at the link above in #2.
4. Get someone to ohm your injectors.. it may just be one bad, not all... i dont often see all go out all at once..
5. Never take your car to anyone, before you do that, you do better working on it yourself. Just cause i know about a Nissan doesn't mean i know about a 1990 Q45..
6. If you would have used the search button foor injectors... all this stuff im saying would have repetitive.