I have a 84 jimmy k5 350 5.7 liter and it was ready for a tune up..so i did that and was running perfect for about a week...i started it one day and it was wantin to die so i kept givin it gas...smoke was shootin out the exhaust..i replaced the computer control module,distributer was fine..im thinkin its the rebuilt carberater inside of it.the spark plugs are fouling too..smoke still comes out of exhaust