Coils fire on one side but don't on other what.

Igniton control module makes them fire from command sent by the Engine Control Unit (computer), which receives its signal when to fire from the Crankshaft and Cylinder Position Sensor located at top left front of engine.

Are you getting battery voltage to the coils?
Ensure the Crank sensor connector is working.
Are you sure it is the ignition system and not engine compression that is causing the problem?