Engine started running roughly. Engine light came on. Checked for fire for spark plugs. Made no difference when I pulled one spark plug wire off. So. That means there was one cylinder not firing? Right? Took spark plug out. Plugged it into the spark plug wire, turned car over, there was spark. Put spark plug back in, restarted the car, it was ideling smoother. Then pulled spark plug wire off the cylinder, again, and it made a difference in the idle. Put the spark plug wire back on, idled fine!
Took it for a test drive (check engine light still on) it started cutting out again at 25 - 30 mph.
So. Fuel delivery problem?