I have had my 68 400 convert since 1978. I had the qudrojet overhauled 8 years ago by someone who I thought was knowledgable. The car got NO kind of gas mileage (10 mpg on the hiway at 2800 rpm's) and the performance was terrible! The lead plug in the bowl was epoxied at the time. However, the fuel bowl always emptied after a couple of days and no raw gas was getting into the crank case.

I finally took the car to a long time friend and nationally known 442 Olds drag racer. After another overhaul, the car runs GREAT and the mileage is way up (wrong float level, primary jets way to big and secondary metering rods oversized). The mechanical advance was also sticky. The lead plug was also epoxied again with a high-tech epoxy

The problem is that the fuel bowl still empties after the car sits a few days. Fuel pump preasure is good but I had heard years back that the fuel pump may allow the gas to be pulled out of the carb and back into the fuel tank.

Has anyone ever heard of a bad check valve in the fuel pump that allows this to happen? I hate to throw a pump at it without input.