I know the FSM says that the pressure should be 31/2-5 psi @ 500 rpm, sometimes when I start it when cold it will give me a hard time starting. I hooked up a pressure indicator and at idle the gauge pulsates as if it has a heartbeat between 31/2 - 5 psi, even when I rev it up to whatever it still pulsates between the same pressures. I have a clear filter on it and it seems to never get fuller than half. Is this a sign of the pump going south?

It depends on the orientation of the filter. it if is sideways then no it will never be full of fuel. You would have to have the filter completely vertical for it to fill with fuel.

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The fuel filters often never fill all the way up. You just never know it until you install a clear one! It seems the fuel flows through the paper element easier than the air does so some air stays trapped in the filter.
Wanna see some vapor lock in action? How do I post my MPG video from my digital camere here?