After replacing both shift solenoids (finding one was broken off, 4T80E) now when I start the car, and immediately put it in reverse, the car doesn't move. It is almost like it needs to build pressure, or like it is low on fluid. If I rev it slightly, or wait about 30 seconds, it will move just fine. Otherwise, I have no other problems. I am thinking it is an accumulator problem, or maybe a bad valve body gasket, but I am not sure. Any suggestions?