Fuel pressure consistently fluctuating on carburated 914, Fuel pressure Options

[reese5997]

Hello,

I have a carburated 73' 914 with fuel pressure issues. I have tried about (5) different fuel pumps from a Faucet with and without a regulator closed circuit to Holly with a regulator open circuit; and have tried 2 different regulators. My current set up for the fuel pump is in the picture. I have an aftermarket return line on the regulator that feeds back into the top of the fuel tank.

The issue that I am having is that my fuel pressure will not remain constant at the small window of 2.5-3.0 required by Raby ACT for his engine I bought. I have found that the performance is degraded when operating outside of this window.

One major issue I found while trouble shooting was that the tiny breather located near the fuel cap was pinched closed; it is now open. Other than that, I cannot find any other issues for why my pressure fluctuates from 2.0 to sometimes 5.0 after setting the pressure to 2.7 then driving for a while and/or when I start it up the next day, after resetting to 2.7, it will be higher or lower. I just about have to adjust it every time I get in the car and in the middle of a drive. Is there a solution for this? java script:emoticon(':confused:',%20'smid_24')

I will post a picture of the engine compartment and return line tomorrow morning during the day light to give a visual of my set up.

Thanks,
-Reese (IMG:style_emoticons/default/confused24.gif)