Keeping this in view, in this paper problem of finding maximum loadability limits has been solved using firefly algorithm. The results obtained using firefly is updated using LIA by increasing load in small steps on PQ buses while voltage constraint is satisfied. LIA gives quality solution because of its ability of modifying solution precisely. Due to presence of LIA optimal solution is obtained for small population size and less number of iterations in FA which otherwise directly affects the quality of solution. The applicability and effectiveness of the proposed approach is tested on 30-bus, 118 bus and 300-bus test systems. From literature survey it is found that approach proposed by [18] has better results than other existing evolutionary algorithms [9, 16-17]. Therefore in this paper results are compared with results obtained in [18]. On comparison it is found that the results obtained using proposed approach are better than [18].