I have a 1978 Cutlass Supreme Brougham(60kmi) with the original 260 (v8) and I have been having a fuel issue now all summer. The motor will start if I dump some gas down the carb, and once its running it will start fine the rest of the day, but if it sits for a day or two no gas pumps out when the pedal is pushed. I posted this problem before and everyone thought the carb was draining internally, so I bought a rebuilt card from National Carbs and installed it, and I am getting the same problem? I loosened the gas cap, I even took a line off the fuel pump to see it was pumping, the fuel filter is new, and I have no idea of what to do next? Is it possible the charcoal canister could be the culprit? If anyone has any thoughts I would appreciate it.

Your carb is probably leaking from internal plug. A simple gasket rebuild type won't help at all. Most likely a crack somewhere. A specialty carb shop will get you fixed up.

try replacing your fuel pump sometimes when the pump goes bad it starts to leak the gasoline back into the fuel tank.

Does your oil smell like gasoline? occassionally fuel pumps can leak into the engine from a hole in the fuel pump. Does the carb get gas if you crank it over and then see if the accelerator pump squirts?

I agree, you pump may be bleeding residual pressure. This would cause a loss of priming.

Jason

That certainly sounds like well plugs leaking. Even if the carb was rebuilt, if they weren't checked properly it could be. Even with fuel pumps loosing prime and such, if the float bowl is full when you shut down and there is no leaks and choking system is working correctly, it should start even if it had no fuel pump. Wouldn't run long but would start. I am assuming the carb is a Q-jet.

Just thought I would give an update, first I appreciate everyones help with thinking this through. It turns out that there is a hole in the fuel pickup in the gas tank. It wasnt until I took off the fuel line before the pump and blew through it I figured this out. The car has only 60kmi original, but it did sit for a few years with only a little gas, in storage not climate controlled here in the Northeast(condensation is to blame). The thing is it will start after dumping gas into the carb, and it will run fine once it gets going, even with the leak, but after a day or two it dries up, I am not really sure how, loses prime I guess, but whats strange is there is no gas in the carb either? And this is a second carb.......

back when your car was new, I owned an autop parts store. We had a lot of poroblems with QJ carbs leaking down after setting. A carb kit was not the fix (in most cases) as the well plugs were leaking (and well plugs were not included in a corb kit. I found a company by the name of TOMCO that produced card kits that included new well plugs and epoxy for sealing them. That kit and a new float would fix 99.9% of QJ. Don't kknow if TOMCO is still around, as I retired from the auto business in 1983. Search it out.