spark problem (?)

I bought a 95 escort wagon with 128,000 and a 1.9 engine from a friend that had it sitting for over a year because the car ran rough (not enough power). I changed the spark plugs (platinum motorcraft) and wires (store brand guaranteed for life), among other minor things. Ran it for a few miles. Still rough. Took the spark plug #1 out and looked brand new (unused). It seems I am running on 3 cylinders. Not sure what to do next. Any suggestions would be incredibly appreciated.
Thanks.

I know this is going to sound dumb. but are you sure the #1 plug wire was all the way on. The reason i ask is i just did the same thing changed plugs and wires started the car and ideled worse with the new stuff. I later figured out the # 1 wire wasnt on all the way. if that isnt the problem i would suggest the coil pack might be bad.

Make sure that the #1 injector is plugged in and working.
Also test for spark in that cylender.