Ignition DIES; 1987 Ford Thunderbird 3.8, throttle body, distributor ignition module.

Hi folks, I'm at my wit's end. I have a 1987 Ford Thunderbird, 3.8, throttle
body injection with the ignition control module on the distributor. It has
118,000 original miles and, up till now, runs perfectly.

The problem started recently as summer came. I drive around a lot and run
the A/C. In town, when it's hot out, the Ignition has started dying intermittantly
at low speed or when stopped at lights, etc.

When it dies, There is NO (zero) Spark coming out of the coil wire, period.
When it cools off a while, it will restart... for a while until hot. It seems to run
fine at night, morning, in the rain, etc., when it's not above 80 degrees or so
outside.

I have:

1) Replaced the ignition module on the distributor 2 times, using a healthy
coat of heat-sink grease.
2) Replaced the ignition coil.
3) Replaced the cap, rotor, wires and plugs.

The battery is new, the starter/relay are new...

Please Help... anyone have any ideas? If this were the old days I'd rip all that
ignition out of there and put an MSD system in and this would go away....

Thanks!

Rando