I just replaced my broken fuel pressure gauge yesterday with a liquid filled one from summit. I'm running a Holley blue electric pump along with a regulator. I started the engine, checked all around the gauge checking for leaks. The gauge was reading 2 psi. I adjusted it to around 5 1/2. Let it idle a few minutes then gave it a few gooid revs. The fuel pressure gauge started dropping down to about 4 psi. Any thoughts? I'm guessing my fuel pump is on it's last leg. What else would cause a drop in fuel pressure?