This phase II trial is studying how well CCI-779 works in treating patients with stage IIIB non small cell lung cancer (with pleural effusion) or stage IV non-small cell lung cancer. Drugs used in chemotherapy, such as CCI-779, work in different ways to stop tumor cells from dividing so they stop growing or die. CCI-779 may also stop the growth of tumor cells by blocking the enzymes necessary for their growth.