Start with a fuel pump volume test. Disconnect the fuel line at the carburetor, slip a piece of rubber hose on, and put the hose into a container. Start the engine and let it idle. There should be enough fuel in the float bowl to idle for some time. The pump should deliver at least a pint in 30 seconds, if it's in good shape and the inlet line isn't restricted.
If the volume is low, connect a pressure/vacuum gauge to the outlet. It should produce about 4 lbs. of pressure, and hold it for a few seconds after the engine is shut off. Then check the inlet. There should be about 10-15 inches of vacuum, and that should stay put for a short time after stopping the engine. Low vacuum or pressure, or an immediate drop to zero is cause to replace the pump. Good results on pressure/vacuum tests but low volume- - - -look for restrictions in the tank-to-pump line, or a blockage inside the tank. Also check any filters or strainers for restrictions.
Jerry
Last edited by Hotrod Lincoln; 09/07/2008 1:28 AM.
