I have a 93 ranger 3.0 auto 4x4 brand new tranny ,m.a.f , .t.p.s. , i.a.c, dist ,coil and plugs and wires . When im drivin it runs good til 45 to 55 mph and it starts jumpin like ridin a bull what else could cause it to do this ? it also has new fuel filter and fuel pump thanks for any help......