My car is a toyota corolla LE. I have a similar problem to that of the Camry. The fire goes down and the car will not move even when the accelerator pedal is down to the floor. It happens mostly in

My car is a toyota corolla LE.  I have a similar problem to that of the Camry.  The fire goes down and the car will not move even when the accelerator pedal is down to the floor.  It happens mostly in traffic.  I change the gear into the parking mode, pull the handbrakes and try to rev the car.  It is only then that the car will move again.  Sometimes the engine goes off and after starting and reving the engine it moves again.  What could the problem be?  My mechanic does not seem to have a clue on what is happening.