1983 Cadillac Deville vehicle not staying on

I have a 1983 Cadillac coupe deville that was running check temp light came on and off shortly after it died out on me and now wont stay running will start but must keep high idled if I attempt to switch gears it dies out have switched fuel filter spark plugs oil and still no luck have had it looked at by a friend and was told it was my throttle body and then have also heard possibly my timing I don't know how to adjust my timing are away to check it. Any advice would be really helpful and possibly any other suggestions would be helpful thanks