The Stovebolt Site Forums The Shop Area Engine Shop Help! I'm stumped

I have a 48' with a 54' 235. It starts great runs great, but when I drive for 2 miles it begins to act like its starving for fuel. What would cause that? It has a new fuel pump, new plugs and wires, new points and condenser. It has a Rochester car with a new kit. When I pull the top off the carb the bowl is full and the float neddle doesn't seem to be sticking. I'm stumped- any ideas?

Check the heat riser and see if it's moving as the engine heats up.


Pete

Do you have a new fuel filter? An old filter can restrict the gas flow and cause this problem.

Kurt

Take the fuel line off that goes into the fuel pump and see if you have a good supply of fuel running from tank to pump. The pickup in the tank could be partially plugged????? Maybe take the gas cap off and see if that makes a difference with the fuel coming out???

Thanks for the suggestions. The heat riser is working and there is a new filter. I'm inclined to think it is a faulty fuel pump. Sometimes when I remove the fuel line to the carb there is gas spraying from the connection. The next time there is no fuel coming from the hose until it's tipped down. When I have someone crank the engine there will be little fuel coming out at first and then only a small dribble.

For whatever it's worth, I had the very same symptoms and it turned out to be a bad ballast resistor. Wouldn't act up until it got it hot.

To test the fuel pump, you can disconnect the fuel line at the carburetor and put it into a catch can. Running the engine at idle speed on the fuel in the float bowl should produce about a pint in 30 seconds. Also check the inlet fitting of the pump for vacuum. It should produce ablut 10-12 inches of vacuum and hold it for a few seconds after the engine is turned off. If the pump has low flow but good vacuum, look for a restriction in the line coming from the tank, or an air leak between the pump and the tank. Sometimes a line will leak air, but not fuel.
Jerry