my 96 delta 88 will have the traction control and abs lites come on sometimes. The abs does not appear to work. the lite will inititally be off and the car will brake normally. then at some random stop the pedal will "crunch" down to the floor stopping the car poorly and the abs lite will come on. The pedal operates stiffly when braking and then goes to the floor. pads rotors and calipers have been replaced. Fluids are fine. any thoughts?