99 mercury sable no spark

99 mercury sable turn over no spark. replaced cam sensor, crank sensor, computer, coil pack, plugs, still no spark. will turn over but will not fire.

Scan the system for codes and post them here. If it's a 12Valve 3.0L it may be a bad cam synchro and a code will appear for this in most cases. The cam synchro is where a distributor would be if this car had one, but it don't.