PLEASE HELP !! when gas is pressed, no response from engine (like gas is not being pressed)

i have a 05 expo XLT with 80k miles. around November, my wife said when he stopped at a red light on the way to work, when she got ready to go, she pressed the gas and it was like she wasnt pressing it at all. i personally have not seen the malfunction, but the first time it happened, we took it to ford, and they couldnt find nothing wrong, so i thought nothing of it. i drove it to and from work for about a monthand then drove it out of town once (300miles one way) and never had the problem again. last week, my wife called me and said it did it again. i've heard that the problem is the torque converter control (TCC) solenoid. if it is the problem, where is the part located, and where can i buy it and how much? PLEASE HELP !!

the selonoid is in the bottom of the transmission on this vehicle

check to see if the throtle cable is intact under the hood it should run across the top of the engine .james