How to check a 90 coil

[DSM Jeff]

My car started running like crap today heading to school. The car felt like it wasn't running on all cylinders. I made it to class and later went out and pulled the plugs. They looked fine and after putting them in, the car ran fine. As soon as I left later in the day and got on it, the car cut out and once again. I hooked up my logger and it came up with an Ignition coil code. Now I've gone through one coil already in the past. This one was good, until today it seems. But I want to know how to check the coil. What prongs in the plug to I check for resistance and what should it read? It is a 4 prong so I can't just go swap coils. Another reason I hate a 90. I also had a spare set of plugs around and swapped them just for giggles and nothing. I'm running rather new magnacore wires as well.
Please if anyone can help guide me in how to check this, i would greatly appreciate it.

 

[luv2rallye]

Matbe this will help: http://www.ecanfix.com/~mdhamilton/1990schematics.html