I took a vacation to Montana back in August. On the way back across Wyoming I stopped for fuel in Cheyenne. Accelerating from a stop light, there was no boost and thick black smoke. This happened again at the next stop light. Drove across Nebraska without incident, but in Missouri at a traffic light I had no boost on take off (no smoke). Then back in Nashville it happened 2-3 times. Hasn't happened since, that was 4-5 months ago / 20,000 miles ago. Only guess I have is that I did idle it for 2-3 hrs while on vacation and maybe it was just cleaning itself out. Never had trouble starting it, though.