Check your battery cables and terminals. This sounds just like what I just had happen the other day. Turned out that my + battery cable terminal was broken and had intermittent contact. Felt like the car hit a brick wall when I tried to go WOT to get on the interstate. Fine the rest of the way home (at 60 MPH at low throttle). Similar thing happened the next morning, except this time the windshield wipers came on. That screamed electrical problem and I spotted the busted cable terminal. 74 cents (at NAPA) and 5 minutes of my time later I was good to go.
