hi, my name is XXXXX XXXXX I will try to help you .
yeah, there is only two things that will do this when the coil pack is only sparking from a few coils or even just one of the towers is not sparking.
that is the coil pack itself or the module ,since you have replaced the coil pack the module would be at fault..
you can ohm out the coil pack using an ohm meter .on each of the coil pairs that is like 2&5-3&6 or 1&4 the meter should read around 5.8 ohms or close to that . since you already replaced the coil pack twice the module (ignition) is bad .
you can get the ignition module checked for free at autozone .not sure if other parts stores have the tester but autozone does .this will test the module under different loads and heat testing ...jazzmaster...