How would one tell when their fuel pump is starting to fail?

 

Get a fuel pressure gauge/tester, and test the fuel pressure. There should be a test valve somewhere on the motor...usually on the fuel rail. I don't remember off the top of my head what the pressure should be though.

 

39 psi is what the pressure is on my 318.

 

Thanks guys, I found a place that said they would test the presure for free.