Before you take it apart, do some troubleshooting. Get a clear line, Ace hardware has the line, just clear PVC hose, and a couple of push on # 10 swivels...If you can't find them, I can send you some. Install the line, run it at high idle-no load and watch the line. No big bubbles, you're good. Big bubbles, your issue is downstream. If that's all good, let it sit overnite and check the hose to see if fuel is there or has bled back. If it's there, you have other issues, pump or injectors. If it's not there, there is a leak. The pump body is pressurized and a leak there usually results in an external leak, but that doesn't mean the th. shaft isn't leaking. There is a quad ring between the gear pump and the pulsation damper. I'd do the damper and the mounting ring 1st. Good luck, take pics.
One other thing I forgot. Sometimes the coils on the fuel shut off, swell. That can cause hard starts and low power. There is also a disc inside there that, if it has a deep groove in the rubber, or has lost a portion of the rubber, or the wave washer has broken, will let the fuel bleed back. It will start hard every time, but run good after it dies finally lite.
HTH
