Power Loss in 5th Gear

[luke1834]

While cruising in 5th gear at approximately 70mph I noticed the car beginning to slow. I began to give the engine more gas and the RPM and speed of the car continued a slow decline. I shifted to 4th and then 3rd while attempting to gain RPM and maintain speed. Even with the car in neutral, I was unable to rev the engine or create any change from idle. When I pulled the car off the road it idled in neutral and there were no unnatural noises or knocks. I then turned the car off and, after checking for fluid leaks and unnatural smells, I started the car. I was able to throttle up and control RPMs just as I normally would. The car performed beautifully for another 45 minutes before the same problem arose. The car then ran 2.5 hours without any problem in 5th gear on the highway under normal driving conditions. No warning lights ever illuminated and so far no one has been able to answer my question as to what went wrong. I surmised a computer/electrical issue since the problem was removed by turning the car off and restarting. The throttle linkage is in fine working order and there are no other obvious physical signs of wear or damage to the engine. Has anyone else had a similar problem or can anyone point me in the direction of the problem/solution?

Thanks!