I WAS DRIVING MY 2004 CHRYSLER PACIFICA WHEN THE ACCELERATION STARTED TO TAPER OFF GRADUALLY. EVENTUALLY IT WENT DOWN TO 25 MPH. I WAS UNABLE TO GO ANY FASTER SO I PULLED ONTO THE SHOULDER. WHEN I TURNED OFF THE ENGINE SMOKE STARTED FLOWING OUT OF THE VENTS IN THE CAR. WITHIN A COUPLE OF MINUTES FIRE WAS SHOOTING INTO THE PASSENGER'S FOOT WELL FROM THE ENGINE. THE POLICE WAS ON THE SCENE IMMEDIATELY AND WAS UNABLE TO PUT IT OUT -TWO FIRE TRUCKS AND 4 POLICE CARS ARRIVED AT THE SCENE. THEY STATED THEY HAD NEVER SEEN A CAR GO UP SO FAST. THERE WAS NOTHING BUT THE SHELL LEFT. I WAS LUCKY THAT I DIDN'T HESITATE TO PULL OVER AND GET OUT OF THE CAR.