New coils is not going to solve weak firing. This is most likely power related or mechanical. Either poor ground (driver board connectors) or flakey +voltage. These two coils you mention are CPU controlled. Software decides how long the coil pulse is. Most likely some kind of physical issue with assembly.
You can not test a diode mounted on a coil. Each end is connected via the coil winding.
The header pins are cut too short on Williams boards of this era. It is a major manufacturing error. I usually replace all header pins on these boards so i can get a reliable solder joint.