On that '89 Buick 3.8 if I had to wager a guess by your symptoms I'd suspect the Ignition Control Module (ICM) is faulty.

On yours I think the AC Delco ICM used the Magnavox style wasted spark Ignition Coils. 

The setup looks like this:

The Magnavox style ignition coil pack was a single unit with all 3 coils in it. One coil went bad you had to replace all 3.

I posted the sketch so you can get an idea of all the electronics in that ICM.

But it's sealed and looks like this:

So if you enlarge that picture and look in the lower left you'll see some holes that shouldn't be there. But sometimes on these ICMs it isn't as visible. Sometimes it's small cracks in that plastic.

Failing electrical components are heat sensitive. But this seal being cracked or burned through adds moisture into the equation and that time it took 24 hours for it to start again could explain that.

Because of your symptoms I'd guess 1st the ICM and then the Crankshaft position sensor. 

The reason is on yours If I remember right, this was a bypass ignition system where the computer doesn't even take control of the ignition spark until 400 rpms. So it's between those two.

Of course, check your battery connections on both cables on both sides. Check the grounds in your engine compartment.

Speaking of grounds those ICMs were grounded in 2 ways. One of them had a ground wire to the ICM bracket and the other was grounded by one of the 3 studs on the ICM to the bracket so make sure those points on the bracket are clean.

So in your case you'll want to check for spark during a NO START. If you aren't getting spark while cranking these 2 components are a likely reason.