I think that you might be doing the test wrong for IG1 and IG3.
When doing the test for IG1, the 3v's needs to be applied to both pins 2 and 4 and for IG3, the 3v's need to be applied to both pins 2 and 3.
If you are doing what I think that you are (just applying 3 volts to one pin each time), then you are not triggering the cylinder detection circuit built into the igniter.
pin 2 (IGT) has to have voltage applied to fire any coil, but if no voltage is allpied to either then only IG2 will fire. To get IG1 to fire, voltage has to also be applied to pin 4 (IGdB) along with pin 2 (IGT) and to get IG3 to fire, voltage has to be applied to pin 3 (IGdA) along with pin 2 (IGT).