the GTO would rev up sitting still and ran like a top, till you went down the road about 2 miles then it would start sputtering and shut off. you could restart and do it all over again. i changed the coil, plugs ,points and condenser and rebuilt the carb. when i got the tank off there was enough water in the bottom of the tank to just cup in the palm of your hand, that's all! and that is all it takes. if there is a lot of water it will hardly run at all, but a small amount is exactly what you are describing,,,,,,,,,,,,,