I purchased a 97 F150 4X4 a couple of months ago and I've noticed an "engine shudder" that occurs when it's about to shift into overdrive. The usually happens when going about 40 mph with the rpm's at about 1800 or 1900. The first time it happened, the "check engine" light came on and the garage told me that cylinder 1 & 2 had misfired and the truck needed a new set of plug wires. About 3 weeks after they were installed (with a new set of platinum plugs) the same thing happened. This time the garage said cylinders 7 & 8 misfired. That's been about a month ago and so far, the check engine light hasn't come on again but I still feel the shudder.
Part of the problem is that I'm living in England and most garages over here dont' have a lot of experience working on trucks. The one that told me cylinder 7 & 8 had misfired is the one that's certified by Ford to carry out warranty work over here.

Any ideas?

 

You might want to have the coil packs checked. The may be breaking down.
Jimmy