1990 dies will start but barley
 

All right guys how it going first time to this site so hopefully i can get some good info and keep coming back for many years to come.
Well I bought this 1990 deville from an older woman about 6 months ago, it only has 60,000 miles on it and she had all the records on it. How ever the car did not run so good it sounded like it needed a tune up, almost sounding like it was missing on one cylinder so i did the tune up and it did not help it still sounds like it is missing. But the real reason im on here is im driving the car today all the sudden i notice a loss of power, i keep driving and it dies, try and start it up and it will barley stay running. if i floor it then it takes a minute to get up the but right when you let off the gas it dies. I checked all the plug wires and i do have fuel presure any ideas???

Have you checked for codes? Bad injectors maybe. You'd have more than a couple not firing to make the car stall.