I had the same problem. Bought a Ignition module and replaced. Didn't do a change on firing all the spark plugs. Took the old one to do a diagnostics and they told the ignition module is working OK. Talked to a Ford Mechanic and he told me could be three things:
- Ignition module
- Cranckase sensor or
- Wiring harness broken or cracked somewhere giving a ground.
The best way to do it is remove the old Ignition module and then take for testing, you will be wasting a couple of dollars by buying dielectric compound that you should be using when you put the old module back, if it tested OK. And no $90 for a component that you didn't need it.