Just started to get my Buick on the road after sitting for the colorado winter. Drove it around the block and noticed when I would slow down/ come to a stop the car will start to stall out or completely die on me. All my lights stayed on and one of the times I was cranking for about 30 seconds before anything happened. This never was an issue last summer when I was daily driving the car. It’s an 85 grand national with the engine from an 86/87. Still pretty new to the electronics in this car so curious if anyone else has had this issue and what it could be causing it. I haven’t seen any ground issues or battery wiring that’s bad. Did spark plugs and wires about 500 miles ago. I have fresh fuel in the tank and it has a hot wire kit so It doesn’t seem to be a fuel issue. I do have a scan master in the car and am still learning to use it properly to diagnose. Any help would be greatly appreciated!