Attach a vacuum gauge to the fuel pump inlet fitting and crank the engine. The pump should develop around 10" of vacuum and hold it for several seconds after the cranking stops. On the output side, test for pressure- - - -2 to 4 PSI is normal, and that should also hold for a short time when the cranking stops. If the pump tests good, look for a restricted inlet line, or a hole that leaks air.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!