What is the best way to check for fuel pump failure?

 

turn the key into the on pos. the unscrew the bolt on top of the fuel filter alittle bit and see if it spray, also when in the on pos. listen either in the back seat, or near the fuel door and see if you hear the buzz noise, meaning it is on.

 

is it possible for the fuel pump only having problem in the higher rpm? let say 6500rpm+ and totally fine at lower rpm?