Try swapping the non-firing coils with firing coils. If the problem follows the coils.. then ther is your answer. If the problem stays with the 1 & 4 coil spots, then it could either be the ignition control module or possibly a wire and plug issue. I am assuming that 1 & 4 are on the same coil pack together? Also check to make sure all the connections from the control module to the pack are securely connected and free of debris.