Bet u can't answer this 1990 Buick leabre problem... JP but i can use ur help!?

Wow sounds like you do have a problem here? Really the only thing I can suggest here and because you said at the end it ran and died and start back up after would be the torque converter solenoid that may be bad here. When the transmission gets hot the TCS stays engage causing the vehicle to stall out when you are coming to a stop. When it cools it unlocks letting the vehicle start again. What you can try doing at this point to see if it is this problem is in front of the transmission unplug the TCS connector and see if it starts up. If it does then the way you repair it is by removing the side transmission pan to get to the solenoid. You should be able to drive with it disconnected but your check engine light will stay on. Now PLEASE keep me posted and let me know if this worked or not?