To establish whether there is a difference in clinical effectiveness of Liposyn II 20 percent as compared with Liposyn III 2 percent in AIDS patients with Pneumocystis carinii pneumonia (PCP). To compare the effects of the two lipid emulsions on immunologic function in AIDS patients. To compare the effect of the two lipid emulsions on HIV load in AIDS patients as measured by reverse transcriptase (RT) in culture. To determine whether a decrease in HIV infectivity is greater in patients given a parenteral feeding regimen containing Liposyn II 20 percent or Liposyn III 2 percent.