coil life?
If there is a spark issue....its probably plugs /wires... I did change plugs on a procharged 540 recently......on the dyno......It had no audible miss, ran clean, but the power was low......changed to new plugs (the cheapest plug I could find) with the car strapped down on the dyno......Still warm putting the new plugs in.....made a pull.....up 150 rwhp.......

