While going to the store my truck developed miss, when you accelerate it starts shaking the entire truck. It felt like it was even moving me around the road. The tach at idle is jumping around some, about 100 rpm either way. After running at a constant speed for a distance it seems to go away, then if you have to stop its right back to shaking when you take off. There is a noticeable power loss that again comes and goes. I ran a code scan and no codes came up. The alternator, I think, is making a noise like a bad barring, but it is rally faint. What do you all think, bad plug, cop, alternator going bad and not sending out the correct amount of voltage? The truck is a 2002 V10 six speed, all stock 181,000 miles. This is the first problem I have had with it. I bought it with 164,000 (all highway) and the previous owner took immaculate care of it. The stack of receipts that came with it is very detailed of what he had done to it. Regularly serviced by ford.

 

OK- its running fine when its cold, once it warmed up it running rough. Now its acting like the throttle is sticking.

 

Sounds like a BAD COP or just a wet hole .... If you can, find someone who can read the misfire counters. That requires the "extended" or "advanced" or whatever setup on the scan tool to read the manufacturer-specific PIDs.

But I'd definitely check for vacuum leaks, dirty MAF, etc, if you can't get someone to read the misfire counters.