Mitsubishi Space Runner

Hello, look I have this problem with the direct injection bencinero engine of this model, the fault is as follows, it reaches 3,000 rpm, and it falls to 2,500, it returns to 3.00 and the same falls again, and reviewed everything electronic and nothing, the check Engine is off, it changes the benzine pump of the pond since it had less than 50 bar that is specified in the manual I would be of information