How do you test a fuel pump to see if it's in good shape or not? I'm having some spuddering issues and wanted to test the pump.

Background
I recently started having a spuddering issue mainly in part throttle. It's not gear, rpm, throttle dependent. However if I really get on the gas get the rpms up and get into boost then it basically goes away. It's become noticeably worse over the course of 1400 miles or so. If I'm at a light and try to take off normally it will stall out on me if it stumbles. It's to the point now that I can't ignore it any longer. Sometimes while idling it will stumble and die out. It's sort of like a light bulb dimming down until off.

When it does spudder, my A/F gauge bounces lean which would make me believe that it's a fuel issue and not an ignition issue, right?

What I've thought
At first I thought it was my cap/rotor/plugs because they needed to replaced anyways. That didn't help at all. It could probably use a new fuel filter as well so I can try that, but I doubt that will fix it. Should I get the injectors flow tested? That only leaves me with the fuel pump and the ignition box/coil as far as I'm aware.

 

You need to find out why its lean at that throttle angle/load. Fuel pump is highly not likely if it runs OK at higher loads and rpm.