Interesting electrical info...
New to the forum... Have owned '95 SSEi for some time now, also had a '96 Park Ave. Lessons learned from both cars that may help others.
1. Positive "stack-cable" for electrical system and starting system is very sensitive to corrosion. Buick was freaking out, looked everywhere for cause, and finally noticed terrible corrosion between each cable and + terminal. Problem went away with new cables.
2. Bad plug wires (as I'm sure many of you know) will cause premature death of coil pack. Replace them if they're even 3 yrs old.
3. True story. While troubleshooting Buick problem used a friend'* Snap-on scan tool. In the course of conversation I learned that these Cars are incredably integrated. He took in an Olds with trans skipping gears and not locking up/locking up prematurely. Rebuilt trans completely (selinoids and all) PROBLEM STILL THERE! Turned out the ignition switch was bad!?! New switch and problem gone.
I have had many more "enjoyable" experiences with both the Bonneville and the Park Ave.