No throttle response 1% of time

I just bought the car listed above from a friend of mine to replace a car for my daughter. I only bought the car as he is the only person I ever drove with where I had to beg him to let me drive as he drives like a Florida retiree. He always ran synthetic oil and has impeccable service maintenance records. He even had his CVT transmission replaced approximately 18,000 miles ago. It still looks like new. Anyway. I wanted to get a couple of things done before I gave it to her, brakes etc. I'm driving it back and forth to work for about 2 weeks now and on 3 occasions, I'm at a full stop and hit the gas and I have almost no power at all. The car does not rev and barely rolls forward. I keep my foot on the gas and in about 5-8 seconds the power slowly kick back In to normal and I can take off normal. This is crazy dangerous as all I could imagine is my daughter trying to make a left turn through traffic. Today I took the throttle body out and cleaned it. Lots of black deposits like it was never cleaned. Took awhile. While I was there, I cleaned the MAF sensor as well. Drove only an hour or so and hasn't happened yet. By the way, the cars check engine light never comes on. I've been reading and I hear about the step motor, accelerator pedal position sensor etc. What else could this be with no codes? Other than this major safety issue, the car runs and drives mint.