I had a problem similar to that when my coil pack went out... check the wiring into the coil pack and may need to replace? I was 700 miles from home on vacation when this happened to me....
2001 ZX3 2.0L Zetec-
Hatch Nation #42
Going through Rebuild See "The TICK Build Thread" for details (http://www.focusfanatics.com/forum/showthread.php?t=289168&referrerid=62897)