My '63 beetle, stock engine, has developed a problem. I drive it almost daily and it starts and idles just as I expect, but underway at a steady cruising speed in high gear it began to cough. I know that's not a great description, but it just sort of coughs or hiccups, then goes on as usual. Sort of as if I switched the ignition off then back on real fast.
I replaced the plugs and points, no change. Heet in the gas with each fillup...no change there either.
Over the past few weeks it has gotten a bit worse. It happens about mid throttle in third and high as I accelerate from a steady speed. Usually a single cough or two, sometimes several in a series and more often once the engine is warmed up to operating temp. There is a noticible roughness at mid throttle also when under load and some vibration.
When this occurs, in either gear, I can press the accelerator to the floor and my car begins to gain speed normally up to (or close to) redline.
New dist cap and wires last year. Valves maybe??? Carb???
