Folks, the old truck with the 226 runs like a sewing machine. However my wife followed me the other day and said she saw one gray/black puff of smoke from the exhaust when I arrived at the bottom of a big hill where the engine braked the truck for about a minute going 40-45 mph. Is that likely un-burned fuel, running too rich, or kinda normal? It doesnt smoke any other time.

 

I would go with the "kinda normal" answer.

 

Thank you sir