i have been having a fuel pressure issue and can not figure out what’s going on. This is on my 383 stroker. I am running an 110gph 8psi mechanical fuel pump going into a Holley 12-880 billet return style regulator. The carb is an AED 750. I have a gauge installed on the regulator and another one at the carb. At the regulator I get good pressure but at the carb I only get 2-3psi. Turning the adjustment screw on the regulator seems to have no effect. Both the regulator and fuel pump are new. I even tried an old mechanical pump I had and still had the same issue. Has anybody ran into this problem? Yes, I know most people don’t run a regulator with a mechanical pump but I needed a way to run my return line back to the tank and the aftermarket pumps don’t have ports for return lines , only the stock style low gph “can” pumps have them. My fuel pump puts out 8psi anyway so I needed to regulate it some. AED wants 6-7psi at the carb.
First, what kind of gauges are you using. If it's the small liquid filled ones, they're notorious for being inaccurate, especially when they heat up.
Are you seeing drive-ability issues caused by low fuel pressure? Seeing that you swapped the pump and it still reads low is telling the gauge is probably faulty.
. Remove the regulator and recheck. Swap gauges, and recheck. I bet one of the gauges or regulator is bad. .
