Thanks for the tip on a Mechanic Brian. I'll check it out.

As for the injectors, here is the flow of events:

1. One day engine wouldn't start. Mechanic sprayed starter fluid into it, and it still wouldn't go. The car sat for about two months.
2. I got a jump starting device, and the engine started and blew out a bunch of smoke. This is when I noticed a rought idle and lack of power.
3. I got injectors from a junk yard and installed them, and it still ran like crap.
4. I took out these injectors, dissassembled them, cleaned them, and put them it, and it stilll ran like crap.
5. I bought rebuilt injectors and put them in, and performace still hasn't changed.

So, to answer the questions, yes, the problem came on fast. Overnight.