Fuel pressure dropping while driving and under acceleration to zero at idle runs 4 lb electric Blue

Ok, help me out here. Refresh my memory. This is a Holley pump with a return line correct???

I don’t know why (other than I’m getting older) but it occurred to me that when I started bypassing fuel with those pumps I always either went into the pump and blocked off the internal bypass with a piece of tubing so it could never open. Then I used a number 8 high speed bypass from Kinsler or someone set at 20 pounds to keep the pump from deadheading and blowing itself apart.

Or, they made a 15 pound bypass spring (IIRC) and I used that with a washer or two under the spring to get the line pressure to 20 psi.

If you have a return line and the buyer pass opens it may be staying open and dropping your fuel pressure.