I did a simple test....sitting in the driveway stationary, looking at my fuel pressure and boost gauge. It idles at 6-7 psi. If I rev the engine, boost goes up to 4 and fuel pressure drops to 4. Does this seem correct? Or does it suggest a collapsing fuel line? If I connect my original hard plastic line the idle is about the same but when I rev the engine fuel pressure goes up to 9 psi. Is the higher pressure air?

Brian

 

It sounds to me like you are collapsing the rubber line. I wouldn't have thunk it, but at high idle the fuel pressure should be higher than at low idle.