01 QX4 POWER STEERING PROBLEM

[BFITZ06]

MY 01 QX4 POWER STEERING STOPPED WOKING ONLY WHEN I AM OUT OF THE GAS, WORKS FINE WHEN I HIT THE GAS. AT IDLE THE TRUCK WILL NOT TURN . THE PUMP AND RACK ARE NOT MAKEING ANY WERD SOUNDS . FLUID IS FINE AND THE LINES ALL LOOK GOOD. THE GUY THAT WORKS ON MY TRUCK HAS NO IDEA WHERE TO START AND I REALLY DONT WANT TO BRING IT TO THE DEALER . HAS ANYONE HAD A PROBLEM LIKE THIS?