1988 Jeep Wagoneer 4.0L mileage: 133,096. This problem started happening when the weather got extremely cold. When I first start the engine, I can smell gas. I can smell it for about twenty minutes after the truck is running. I checked on the ground below the engine and I do not see any signs of a leak. There were other days when it was not as cold, and I did not smell a thing.