Coincidentally, I had a problem with fuel pressure today. Wasn't getting any pressure at the carb inlet. I tested each intersection working my way back and had no pressure. However, when I removed the line at the fuel pump inlet, I got pressure at the outlet. I put a hose from the pump inlet to a can of gas and started the car up after a few cranks. So this isolated the tank from the rest of the pump system; my line from the tank is clogged.
Lesson: a pump needs to draw in order to push. If there's no fuel pressure, it's not necessarily the fault of the pump.
