It seems like you might be mixing up some details. "Running on Empty" (1988), directed by Sidney Lumet, isn't about Mort finding out he has less than a year to live or joining a dating service. The film actually follows the story of a family of political activists who are on the run from the FBI. The parents, played by Christine Lahti and Judd Hirsch, have been fugitives for years, and their son, Danny (River Phoenix), struggles with his desire to live a normal life while dealing with the consequences of his parents' actions. If you meant a different film or need more details on this one, just let me know!