volvo 240 1993 fuel pump
 

My 93 is making a strange noise that is intermittent buzzing sound that is coming from the fuel pump (not the in tank pump). My question is, is there anyway i can test the in tank pump to make sure it isnt actually the in tank pump going out making the normal in line pump work twice as hard? the in tank pump is a 40$ fix vs 100+ for the in line

Thanks!