[Capri306]

I had a similar problem and it ended up being the TFI-IV module, or ignition module in English. It would be a complete DOG after a little high-speed driving on the expressway, bogging and coughing the whole way home. You could be having the same condition. Have it checked at a parts store for free if you like, but I'd replace it anyway because the factory modules tended to die before or around the 100k mark. And yes, Ford modules are finnicky like that; they work for a while, then sputter once warm. Bad transistors (internal part) are to blame, along with bad heatsink engineering.

Have you ever changed the HEGO (oxygen) sensors? If not, those should be next on your shortlist. EEC-IV's rely heavily on HEGO signal to run properly.

After that, I would suspect a fuel pump or injector, but it's EXTREMELY hard to tell without actually hearing the car running. Is it just one cylinder not firing, or like a "lean-out" condition? Any check engine light?

I will say this once: get rid of those Bosch Platinum +4 spark plugs NOW.