Car runs for a few seconds then dies

If the carb (Carter BBD?, you didn't tell us) and other engine controls are 1985, you have your hands full. That was the last-gasp effort of carburetors w/ complicated vacuum controls, O2 feedback solenoid, etc. Not much documentation on how it is supposed to work and many things to go wrong. As mentioned, could be spark instead of fuel. Do you have the "lean burn" ignition system? You didn't give us much to go on.