I bought a 86 fleetwood brougham that i bought from someone that had it sitting for about a year. at first it ran well but it was a little weak. a couple months after i bought it it began to die about 15 minutes into driving it in the morning, i would try to start it but it would just crank over or start and run really bad. later in the day it would start with a big cloud of dark smoke. I changed the fuel filter and found a few craked vacuum lines so i fixed that and it ran better and didn't die. Now a few weeks later it will not go above about 30mph and it wont go up any hill with out slowing down and dying. What should i do? it sounds fuel related but I dont know what to do from here. any help or suggestions would be great. thanks in advance.