I have a 95 f250 that I have had for years without a spec of trouble, but today I started it and got a real rough idle (miss). Tried increasing the rpm to get it to smooth out, but it just ran worse. I shut it down and let it set for just a minute and started it again with the same result. Next, I performed some work on a noisy brake and started it again after letting it set for about a half an hour and it ran smooth. I would appreciate any thoughts you may have on this.