Power steering feels like the power steering has little jurks in the wheel then it will go out if you turn the car off the turn it back on it is ok for a little bit then does it again

SOURCE: 2001 F-250 4x4 super duty steering problem

sounds like the problem is in the valving in the steering box. You may have to get a new steering box. i would get it checked.

SOURCE: 2004 Ford F250 Superduty Truck Steering problems

I have had this same problem after thorough checking it ended up being a bad steering box. after replacing the box it was fine

SOURCE: Ford Focus 2006 loose power

if its auto it sounds like the transmisson is sllipping no quick fix
if its manual the clucth is slipping try adjusting if there is no adjustment then clutch needs replacing

SOURCE: Steering hard /loosing pwer at 40-55mph

check power steering hoses. for leak it sound like fluid getting on belt causing slipping.causing alternator problems.alternator cant charge if belt slipping.fluid getting on exhaust manifold making it smoke it also can catch fire.so look at power steering pressure hose sound like it rupture causing lost fluid and hard steering.

SOURCE: 1999 ford ranger xlt 4x4 off road and the 4 wheel

check the hubs for vacuum leaksthe lines should follw the abs sensor wires