anyone have any idea what would cause my 79 G20 van would stumble/cutout during right hand turns. I have replaced the carb (edelbrock same as used for 150,000 miles), spark plugs and wires, checked vacuum lines but still does same thing. floats in carb were rechecked and are correct. van has built (but tired) 350 engine and 2-1/2 duel exhaust with high flow converters and turbo mufflers. any thoughts are appreciated.

 

How much fuel is in tank when this happens?

 

I am betting its a fuel slosh issue or you might have a partially blocked fuel pickup in the tank. How old is the fuel pump?

 

fuel pump is a few years old but works well, still runs van easily at 80 plus mph and 5000 rpm without missing a beat (as long as it is straight line). the other day I disconnected the fuel line from the tank at the pump and connected a hose from a gas can and took it for a drive. it drove with no problems, I then reconnected the tank fuel line and it acted up again. I have not had a chance to inspect the lines back to the tank. what I can't understand is why it misses so quickly in a turn when feeding fuel from the tank. the fuel in the carb should keep it running. next i'm going to install a fuel pressure gauge in the line to see if it's loosing pressure before dropping the tank.

 

Having a similar issue in 1989 G20...did you find a solution? Did you have to replace the fuel pump?