91 PA no spark on #2

[flyerdan]

Have a 91 PA, 3.8 with 72,000 miles. Recently the car began missing quite badly, managed to limp home and changed the plugs. Didn't cure it. Replaced the coil pack, that seemed to solve the problem, as the #2 post was competely dead. Now, after 221 miles, the exact same problem has reoccured. The probability of a coil pack failure on the same cylinder seems quite unlikely. I did notice that there was an occasional stumble at a stoplight before the complete drop out tonight. I did not replace the ignition module, as I understood that this was usually an all or nothing component, not susecptible to partial failure.
Any ideas on what to try next? Thanks, Dan.

[suzqlar2]

First, measure resistance of coil, should be 12000 ohms, +- 1000. Next, substitute 2 plug wires know to be good, even if they test good. Have seen many aftermarket coil not last. Also, if #5 plug is fouled, #2 may missfire. If these are not it, it is the module, and yes they can be weak and intermittent.

[flyerdan]

Checked the old coil pack, 11.63k, 11.40k, 11.52k, all back terminals are about 1.0 ohm. The plugs that I replaced all looked quite good, even the one that wasn't firing only smelled slightly gassy. Looks like its time for a $100+ ignition module.
Thanks for the testing tips.