Holley sniper efi 2

Several things here.
1. Holley regulators have been failing left and right. We sell a ton of sniper 2 equipped engines, and have had many customers call back and buy our billet regulator because their holley regulator failed. Just saved the day for a guy driving his truck 5 hours home with one of these, when his holley diaphragm blew out. EFI Billet Aluminum Fuel Pressure Bypass Regulator - 40-75 PSI and -6AN ORB

2. Inline pumps are pushers, not pullers. Needs mounted as low as possible.
3. What fuel filter is on it? Not impossible you stirred up some junk in the tank, and a 5 or 10 micron fuel filter is clogged.
4. If your return line is not dropped below the fuel level, you can aerate the fuel when low, causing pressure drop.
5. I have also seen an increase in failed walbro type inline pumps. They used to be the go-to, but I have seen plenty fail recently.

Hope that helps.