You should be able to check the system for trouble codes. You can do an internet search for the procedure and the code meanings.
You may need a shop manual to make the actual repairs.
When the engine is turning without ignition but is injecting fuel, that fuel and air is pumped through the engine into the exhaust where it will build up until sooner or later it will ignite with explosive force.
This is what happens when there is a bad misfire due to an ignition fault.
I suggest you check your spark plugs and ensure there is a powerful spark available at each spark plug.
The caliper is bolted on by sliding pins that allow the caliper to adjust itself. I would assume the sliding pins are stuck. The bolts slide inside the carrier that holds the calipers.
Try changing the temperature sending unit. This regulates the cold start mode and it appears it's still in cold start mode and still feeding it too much fuel, causing a flooding condition and making it die at stops. When you depress throttle to go, it's still getting too much fuel and wants to bog and die on take-off.
1989 1997 CADILLAC DEVILLE REPAIR MANUAL
Maybe bearing of the car has worn out.
Check it out.
If there's a problem you can fix it using this manual link I have attached.
I feel sorry for you, after reading your problem, but don't worry you visit the
Reliable-Store they will help you for sure.
1989 1997 CADILLAC DEVILLE REPAIR MANUAL
Have heard of condensation causing that problem on distributor caps. Don't know why it couldn't be a problem for coils. Maybe a crack getting moisture inside.
