My 1999 Suburban sometimes looses power steering at low RPMs. If I rev it up just a little it kicks back and seems to work fine. The pump was replaced, but that didn't fix it. I disconnected the wires to the EVO thinking maybe the sensor on the column was bad, but that didn't fix it either. Any other ideas? Maybe a sticky flow control valve? I'm not sure if that would have gotten replaced with the pumpp or not. Thanks in advance.