I was driving my 1949 Dodge Wayfarer business coupe at 55 mph when the speed slowed to 35 mph. Stepping on the accelerator didn't increase the speed. But after 30 seconds the car resumed at a highway speed. It has happened twice. The carburetor has been rebuilt and the glass bowl in the fuel pump is clean. The car's odometer shows only 19,000 miles, but I'm sure it isn't 119,000 miles. The car runs fine, otherwise, all the gauges work as does the fluid drive. The car usually runs fine. I drove it home 100 miles the day before a snowstorm in November and it ran like a top.