In need off advice
 

hey im mr.wilson. Just bought a 1998 dakota sport 3.9 v6 with about 93,450 miles.just replaced the variable speed sensor,going to be replacing spark plug wires distributor cap and plugs next. but heres the problem. truck starts great idles great but when driving it seems like if you hit a certain speed about 55 or higher the truck will shut off, im only aware that it's truned off when i go to turn or stop i'll have limited brakes and no steering. put truck in netrual and start it back up. fires right up no problems. it only turns off once in awhlie it's not an all the time thing. if anyone has any help or ideas let me know, makes me nervous to drive long distances