Jaguar Repair: 1987 xj6 blowing smoke, exhaust smoke, excess fuel

Question
Hi. I have a 1987 xj6 Vanden Plas 4.2. The car run good (has a slight miss when cold) and doesn't burn oil,  but occasionally when I start it up it blows out a lot of smoke from the exhaust and under the hood. This lasts for about 30 seconds then quits and the car will be fine for a week or two. It smells like exhaust fumes. Thanks Brian

Answer
Hi Brian,
Any smoke from under the hood can be dangerous and you must determine where it is coming from. Raise the hood before you have someone start it and look to see where it is coming from. Also any exhaust smoke should be viewed from behind the car and noted what color the smoke is. White is either coolant or brake fluid, light blue is oil and black it excess fuel. This car has two CATs and they can be destroyed by something in the exhaust.
Howard