I am the proud owner of a 92 Cadillac DeVille 4.9 V8
Soemtimes it will not stay running and have to restart several times. On a trip when the temperature outside gets above 82 the car will start missing, bucking and won't run. I have to pull over for 5-10 minutes and it will be okay for a while. I put octane booster in the tank and that helps. I use Hi-test gas. At least that is what the pumps say. Sometimes I wonder. Anyone else have a problem like this or any suggestions? Also the fuel gage is playing tricks. It will register empty when full and the mileage shows 56 mpg. Hey I wish. :D
Thanks:)

see if you have any stored codes.

If your fuel gage is showing one reading, and you know that your tank level is not the same, then it's probably your sending unit (which may be mounted in your gas tank). I've read of a bunch of sending units in Caddy's going bad, and I had to have the one in the Vette replaced twice, still under warranty, after about 2 years after I bought it.